U.S. patent application number 17/023552 was filed with the patent office on 2021-01-07 for shovel.
The applicant listed for this patent is SUMITOMO HEAVY INDUSTRIES, LTD.. Invention is credited to Junichi MORITA.
Application Number | 20210002851 17/023552 |
Document ID | / |
Family ID | |
Filed Date | 2021-01-07 |
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United States Patent
Application |
20210002851 |
Kind Code |
A1 |
MORITA; Junichi |
January 7, 2021 |
SHOVEL
Abstract
A shovel (100) according to embodiments of the present invention
includes a lower travelling body (1), an upper pivot body (3)
pivotably mounted to the lower travelling body (1), an excavation
attachment (AT) rotatably mounted to the upper pivot body, and a
controller (30) provided to the upper pivot body (3). The
controller (30) is configured to autonomously perform a compound
operation including an operation of the excavation attachment (AT)
and a pivot operation. The controller (30) may be configured to, in
response to an automatic switch (NS2) provided in a cabin (10)
mounted to the upper pivot body (3) being operated, autonomously
perform the compound operation.
Inventors: |
MORITA; Junichi; (Kanagawa,
JP) |
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Applicant: |
Name |
City |
State |
Country |
Type |
SUMITOMO HEAVY INDUSTRIES, LTD. |
Tokyo |
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JP |
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Appl. No.: |
17/023552 |
Filed: |
September 17, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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PCT/JP2019/011244 |
Mar 18, 2019 |
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17023552 |
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Current U.S.
Class: |
1/1 |
International
Class: |
E02F 3/43 20060101
E02F003/43; E02F 9/20 20060101 E02F009/20 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 20, 2018 |
JP |
2018-053219 |
Claims
1. A shovel comprising: a lower travelling body; an upper pivot
body pivotably mounted to the lower travelling body; an attachment
attached to the upper pivot body; and a controller provided to the
upper pivot body, wherein the controller is configured to
autonomously perform a compound operation including an operation of
the attachment and a pivot operation.
2. The shovel as claimed in claim 1, further comprising: an
operation lever provided in a cabin mounted to the upper pivot
body, wherein the controller performs the compound operation for
one of the operation lever.
3. The shovel as claimed in claim 1, wherein the controller is
configured to, in response to a first switch provided in a cabin
mounted to the upper pivot body being operated, autonomously
perform the compound operation.
4. The shovel as claimed in claim 1, further comprising: a posture
detection device that obtains information regarding a posture of
the attachment, wherein the controller is configured to calculate a
target trajectory drawn by a predetermined point in the attachment
based on the information obtained by the posture detection device
and autonomously perform the compound operation so that the
predetermined point moves along the target trajectory.
5. The shovel as claimed in claim 4, wherein the controller is
configured to perform the compound operation repeatedly and is
configured to change the target trajectory for each execution of
the compound operation.
6. The shovel as claimed in claim 4, further comprising: a second
switch provided in a cabin mounted to the upper pivot body, wherein
the controller is configured to, in response to the second switch
being operated, obtain the information regarding the posture of the
attachment.
7. The shovel as claimed in claim 1, wherein the controller is
configured to autonomously perform the compound operation during an
operation of a first switch provided in a cabin mounted to the
upper pivot body or during a pivot operation in a state where the
first switch is operated.
8. The shovel as claimed in claim 1, further comprising: a display
device, wherein the display device is configured to display a
relative positional relationship between the shovel and a dump
truck.
9. The shovel as claimed in claim 1, wherein the compound operation
is a boom up pivot operation for loading a to-be-loaded object onto
a platform of a dump truck, and the controller is configured to
autonomously perform the compound operation such that the
to-be-loaded objects are loaded in an order from an inner side to
an front side of the dump truck.
10. The shovel as claimed in claim 4, further comprising: a display
device, wherein the display device is configured to display the
target trajectory.
11. The shovel as claimed in claim 1, further comprising: a display
device, wherein the compound operation is a boom up pivot operation
for loading a to-be-loaded object onto a platform of a dump truck,
and the display device is configured to display information
regarding an excavation completion position that is a start
position of the compound operation.
12. The shovel as claimed in claim 1, further comprising: a display
device, wherein the compound operation is a boom up pivot operation
for loading a to-be-loaded object onto a platform of a dump truck,
and the display device is configured to display information
regarding an earth removal start position that is a completion
position of the compound operation.
13. The shovel as claimed in claim 4, wherein the controller is
configured to determine whether a deviation between the
predetermined point and the target trajectory is within an
allowable range.
14. The shovel as claimed in claim 1, wherein if a distance between
a control reference point and a dump truck is less than a
predetermined value, the controller limits velocity of a work
portion with a predetermined upper limit value.
15. The shovel as claimed in claim 1, wherein if a distance between
a control reference point and a dump truck is less than a
predetermined value, the controller decreases velocity of a work
portion.
16. The shovel as claimed in claim 1, wherein the controller
composes a feedback loop for a position of a control reference
point with respect to a target trajectory and composes a feedback
loop regarding a rotation angle of the upper pivot body based on a
detected value of the rotation angle of the upper pivot body.
17. The shovel as claimed in claim 1, wherein the controller sets a
target trajectory in a boom down pivot operation.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation application of
International Application No. PCT/JP2019/011244 filed on Mar. 18,
2019, which claims priority to Japanese Patent Application No.
2018-053219 filed on Mar. 20, 2018. The contents of these
applications are incorporated herein by reference in their
entirety.
BACKGROUND
Technical Field
[0002] The present disclosure relates to shovels.
Description of the Related Art
[0003] Conventionally, a hydraulic excavator equipped with a
semi-autonomous excavation control system is known (see Patent
Document 1). The excavation control system is configured to, if a
predetermined condition is satisfied, autonomously perform a boom
up pivot operation.
SUMMARY
[0004] However, the above-stated excavation control system is
configured to autonomously perform the boom up pivot operation
without notifying the operator if a predetermined amount of the
boom up operation and a predetermined amount of the pivot operation
are simultaneously performed by the operator, that is, regardless
of the operator's intention. Therefore, there is a risk that the
boom up pivot operation may be performed against the operator's
intention.
[0005] Accordingly, it is desirable to provide a shovel that can
autonomously perform a compound operation including the pivot
operation in accordance with the operator's intention.
[0006] A shovel according to an embodiment of the present invention
includes a lower travelling body, an upper pivot body pivotably
mounted to the lower travelling body, an attachment attached to the
upper pivot body, and a controller provided to the upper pivot
body, and the controller is configured to autonomously perform a
compound operation including an operation of the attachment and a
pivot operation.
[0007] According to the above-stated solution, a shovel that can
autonomously perform a compound operation including a pivot
operation in accordance with the operator's intention is
provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1A is a side view of a shovel according to an
embodiment of the present invention;
[0009] FIG. 1B is a top view of a shovel according to an embodiment
of the present invention;
[0010] FIG. 2 is a diagram for illustrating an exemplary
arrangement of a hydraulic system equipped to a shovel;
[0011] FIG. 3A is a diagram of a portion of the hydraulic system
related to operations for an arm cylinder;
[0012] FIG. 3B is a diagram of a portion of the hydraulic system
related to operations for a pivot hydraulic motor;
[0013] FIG. 3C is a diagram of a portion of the hydraulic system
related to operations for a boom cylinder;
[0014] FIG. 3D is a diagram of a portion of the hydraulic system
related to operations for a bucket cylinder;
[0015] FIG. 4 is a functional block diagram of a controller;
[0016] FIG. 5 is a block diagram of an autonomous control
function;
[0017] FIG. 6 is a block diagram of an autonomous control
function;
[0018] FIG. 7A is a diagram for illustrating one exemplary aspect
of a work site;
[0019] FIG. 7B is a diagram for illustrating one exemplary aspect
of a work site;
[0020] FIG. 8 is a flowchart of one exemplary calculation
operation;
[0021] FIG. 9 is a flowchart of one exemplary autonomous
operation;
[0022] FIG. 10A is a diagram for illustrating another aspect of a
work site;
[0023] FIG. 10B is a diagram for illustrating another aspect of a
work site;
[0024] FIG. 10C is a diagram for illustrating another aspect of a
work site;
[0025] FIG. 11 is a diagram for illustrating an exemplary image
displayed in autonomous control;
[0026] FIG. 12 is a block diagram for illustrating another
exemplary arrangement of an autonomous control function;
[0027] FIG. 13 is a block diagram for illustrating another
exemplary arrangement of an autonomous control function;
[0028] FIG. 14 is a diagram for illustrating an exemplary
arrangement of an electric operation system; and
[0029] FIG. 15 is a schematic diagram for illustrating an exemplary
arrangement of a shovel management system.
DETAILED DESCRIPTION
[0030] First, a shovel 100 as an excavator according to an
embodiment of the present invention is described with reference to
FIGS. 1A and 1B. FIG. 1A is a side view of the shovel 100, and FIG.
1B is a top view of the shovel 100.
[0031] In this embodiment, a lower travelling object 1 of the
shovel 100 includes a crawler 1C. The crawler 1C is driven by a
driving hydraulic motor 2M equipped in the lower travelling object
1. Specifically, the crawler 1C includes a left crawler 1CL and a
right crawler 1CR. The left crawler 1CL is driven by a left
travelling hydraulic motor 2ML, and the right crawler 1CR is driven
by a right travelling hydraulic motor 2MR.
[0032] An upper pivot body 3 is pivotably mounted to the lower
travelling body 1 via a pivot mechanism 2. The pivot mechanism 2 is
driven by a pivot hydraulic motor 2A equipped in the upper pivot
body 3. However, the pivot hydraulic motor 2A may be a pivot
electric generator as an electric actuator.
[0033] A boom 4 is mounted to the upper pivot body 3. An arm 5 is
attached to a tip of the boom 4, and a bucket 6 is attached to the
tip of the arm 5 as an end attachment. The boom 4, the arm 5, and
the bucket 6 compose an excavation attachment AT, which is one
example of an attachment. The boom 4 is driven by a boom cylinder
7, the arm 5 is driven by an arm cylinder 8, and the bucket 6 is
driven by a bucket cylinder 9.
[0034] The boom 4 is rotatably supported up and down with respect
to the upper pivot body 3. A boom angle sensor S1 is mounted to the
boom 4. The boom angle sensor S1 can detect the boom angle
.beta..sub.1, which is the rotation angle of the boom 4. The boom
angle .beta..sub.1 may be the rising angle from the state where the
boom 4 is most lowered. Therefore, the boom angle .beta..sub.1 is
maximized when the boom 4 is most raised.
[0035] The arm 5 is supported pivotally relative to the boom 4.
Then, an arm angle sensor S2 is mounted to the arm 5. The arm angle
sensor S2 can detect the arm angle .beta..sub.2, which is the
rotation angle of the arm 5. The arm angle .beta..sub.2 may be the
opening angle from the most closed position of the arm 5.
Therefore, the arm angle .beta..sub.2 is maximized when the arm 5
is most opened.
[0036] The bucket 6 is supported rotatably relative to the arm 5. A
bucket angle sensor S3 is mounted to the bucket 6. The bucket angle
sensor S3 can detect the bucket angle .beta..sub.3, which is the
rotation angle of the bucket 6. The bucket angle .beta..sub.3 is
the opening angle from the most closed position of the bucket 6.
Therefore, the bucket angle .beta..sub.3 is maximized when the
bucket 6 is opened most.
[0037] In the embodiments shown in FIGS. 1A and 1B, each of the
boom angle sensor S1, the arm angle sensor S2, and the bucket angle
sensor S3 includes a combination of an acceleration sensor and a
gyro sensor. However, it may include only the acceleration sensor.
Also, the boom angle sensor S1 may be a stroke sensor, a rotary
encoder, a potentiometer, an inertia measuring device, or the like
mounted on the boom cylinder 7. The same applies to the arm angle
sensor S2 and the bucket angle sensor S3.
[0038] A cabin 10 is provided in the upper pivot body 3 as an
operator's cab, and a power source such as an engine 11 is
installed therein. Further, an object detection device 70, a
capturing device 80, a body tilt sensor S4, and a pivot angular
velocity sensor S5 are equipped in the upper pivot body 3. An
operation device 26, a controller 30, a display device D1, a sound
output device D2, and the like are provided inside the cabin 10.
For convenience, it is assumed in the upper pivot body 3 that the
side where the excavation attachment AT is mounted is the front
side and the side where the counterweight is mounted is the rear
side.
[0039] The object detection device 70 is configured to detect an
object that exists around the shovel 100. The object may be, for
example, a person, an animal, a vehicle, a construction machine, a
building, a wall, a fence, or a hole, or the like. The object
detection device 70 may be, for example, an ultrasonic sensor, a
millimeter wave radar, a stereo camera, a LIDAR, a distance image
sensor, or an infrared sensor, or the like. In this embodiment, the
object detection device 70 includes a front sensor 70F mounted to
the front end of the top surface of the cabin 10, a rear sensor 70B
mounted to the rear end of the top surface of the upper pivot body
3, a left sensor 70L mounted to the left end of the top surface of
the upper pivot body 3, and a right sensor 70R mounted to the right
end of the top surface of the upper pivot body 3.
[0040] The object detection device 70 may be configured to detect a
predetermined object within a predetermined area that is set around
the shovel 100. Namely, the object detection device 70 may be
configured to identify the type of object. For example, the object
detection device 70 may be configured to distinguish between a
person and an object other than the person.
[0041] A capturing device 80 is configured to capture a periphery
of the shovel 100. In this embodiment, the capturing device 80
includes a rear camera 80B mounted to the rear end of the top
surface of the upper pivot body 3, a left camera 80L mounted to the
left end of the top surface of the upper pivot body 3, and a right
camera 80R mounted to the right end of the top surface of the upper
pivot body 3. The capturing device 80 may include a front
camera.
[0042] The rear camera 80B is positioned to be adjacent to the rear
sensor 70B, the left camera 80L is positioned to be adjacent to the
left sensor 70L, and the right camera 80R is positioned to be
adjacent the right sensor 70R. If the capturing device 80 includes
a front camera, the front camera may be positioned to be adjacent
to the front sensor 70F.
[0043] An image captured by the capturing device 80 is displayed on
the display device D1. The capturing device 80 may be configured so
that a viewpoint converted image, such as a bird's-eye image, can
be displayed on the display device D1. For example, the bird's-eye
image may be generated by combining respective images that are
output by the rear camera 80B, the left camera 80L, and the right
camera 80R.
[0044] The capturing device 80 may be utilized as the object
detection device 70. In this case, the object detection device 70
may be omitted.
[0045] The body tilt sensor S4 is configured to detect the tilt of
the upper pivot body 3 relative to a predetermined plane. In this
embodiment, the body tilt sensor S4 is an acceleration sensor that
detects an inclination angle about the front and rear axes and an
inclination angle about the right and left axes of the upper pivot
body 3 with respect to the horizontal plane. For example, the front
and rear axes and the left and right axes of the upper pivot body 3
may pass through a shovel center point, which is one point on the
pivot axis of the shovel 100 perpendicular to each other.
[0046] The pivot angular velocity sensor S5 is configured to detect
the pivot angular velocity of the upper pivot body 3. In this
embodiment, the pivot angular velocity sensor S5 is a gyro sensor.
The pivot angular velocity sensor S5 may be a resolver, a rotary
encoder, or the like. The pivot angular velocity sensor S5 may
detect the pivot velocity. The pivot velocity may be calculated
from the pivot angular velocity.
[0047] Hereinafter, each of the boom angle sensor S1, the arm angle
sensor S2, the bucket angle sensor S3, the body tilt sensor S4, and
the pivot angle sensor S5 may be also referred to as a posture
detection device.
[0048] The display device D1 is a device for displaying
information. The sound output device D2 is a device for outputting
sound. The operation device 26 is a device used by an operator to
operate an actuator.
[0049] The controller 30 is a controller for controlling the shovel
100. In this embodiment, the controller 30 is arranged with a
computer including a CPU, a RAM, a NVRAM, a ROM and others. The
controller 30 reads programs corresponding to respective functions
from the ROM and loads the programs into the RAM to cause the CPU
to perform operations corresponding to the respective functions.
The functions may include, for example, a machine guidance function
to guide manual operations by an operator for the shovel 100 and a
machine control function to automatically assist the manual
operations by the operator for the shovel 100.
[0050] Next, an exemplary arrangement of a hydraulic system
equipped to the shovel 100 is described with reference to FIG. 2.
FIG. 2 is a diagram for illustrating an exemplary arrangement of
the hydraulic system equipped to the shovel 100. In FIG. 2, a
mechanical power transmission system, a hydraulic oil line, a pilot
line, and an electrical control system are illustrated as a double
line, a solid line, a dashed line and a dotted line,
respectively.
[0051] The hydraulic system of the shovel 100 mainly includes an
engine 11, a regulator 13, a main pump 14, a pilot pump 15, a
control valve 17, an operation device 26, an discharge pressure
sensor 28, an operation pressure sensor 29, and a controller 30,
and the like.
[0052] In FIG. 2, the hydraulic system circulates the hydraulic oil
from the main pump 14, which is driven by the engine 11, to a
hydraulic oil tank via a center bypass line 40 or a parallel line
42.
[0053] The engine 11 is a driving source of the shovel 100. In this
embodiment, the engine 11 may be a diesel engine that operates to
retain a predetermined number of rotations, for example. An output
shaft of the engine 11 is coupled to respective input shafts of the
main pump 14 and the pilot pump 15.
[0054] The main pump 14 is configured to supply the hydraulic oil
to the control valve 17 via a hydraulic oil line. In this
embodiment, the main pump 14 is a swashplate type variable
displacement hydraulic pump.
[0055] The regulator 13 is configured to control the discharge
volume (push back volume) of the main pump 14. In this embodiment,
the regulator 13 controls the discharge volume (push back volume)
of the main pump 14 by adjusting the swashplate tilt angle of the
main pump 14 in response to a control command from the controller
30.
[0056] The pilot pump 15 is configured to supply the hydraulic oil
to a hydraulic control device including the operation device 26 via
a pilot line. In this embodiment, the pilot pump 15 is a fixed
displacement hydraulic pump. However, the pilot pump 15 may be
omitted. In this case, the function performed by the pilot pump 15
may be implemented by the main pump 14. Namely, in addition to the
function of supplying the hydraulic oil to the operation device 26,
the main pump 14 may include a function of supplying the hydraulic
oil to the operation device 26 or the like after the pressure of
the hydraulic oil is lowered by a squeeze or the like.
[0057] The control valve 17 is configured to control the flow of
the hydraulic oil in the hydraulic system. In this embodiment, the
control valve 17 includes control valves 171 to 176. The control
valve 175 includes a control valve 175L and a control valve 175R,
and the control valve 176 includes a control valve 176L and a
control valve 176R. The control valve 17 can selectively supply the
hydraulic oil discharged by the main pump 14 to one or more
hydraulic actuators through the control valves 171 to 176. The
control valves 171 to 176 control the flow of the hydraulic oil
from the main pump 14 to the hydraulic actuator and the flow of the
hydraulic oil from the hydraulic actuator to the hydraulic oil
tank. The hydraulic actuator includes a boom cylinder 7, an arm
cylinder 8, a bucket cylinder 9, a left travelling hydraulic motor
2ML, a right travelling hydraulic motor 2MR, and a pivot hydraulic
motor 2A.
[0058] The operation device 26 is a device used by an operator to
operate an actuator. The actuator includes at least one of a
hydraulic actuator and an electric actuator. In this embodiment,
the operation device 26 supplies the hydraulic oil discharged by
the pilot pump 15 to a pilot port of the corresponding control
valve in the control valve 17 via a pilot line. The pressure (pilot
pressure) of the hydraulic oil supplied to each of the pilot ports
is the pressure corresponding to the operation direction and the
operation amount of levers or pedals (not shown) of the operation
device 26 corresponding to each of the hydraulic actuators.
However, the operation device 26 may be electrically controlled
rather than the pilot pressure type as described above. In this
case, the control valve in the control valve 17 may be an
electromagnetic solenoid spool valve.
[0059] The discharge pressure sensor 28 is configured to detect the
discharge pressure of the main pump 14. In this embodiment, the
discharge pressure sensor 28 outputs the detected value to the
controller 30.
[0060] The operation pressure sensor 29 is configured to detect
operational contents of the operation device 26 by an operator. In
this embodiment, the operation pressure sensor 29 detects the
operation direction and the operation amount of levers or pedals of
the operation device 26 corresponding to respective actuators in
the form of pressure (operation pressure) and outputs the detected
value as operation data to the controller 30. The operational
contents of the operation device 26 may be detected using sensors
other than the operation pressure sensor.
[0061] The main pump 14 includes a left main pump 14L and a right
main pump 14R. The left main pump 14L is configured to circulate
the hydraulic oil to the hydraulic oil tank through the left center
bypass line 40L or the left parallel line 42L. The right main pump
14R is configured to circulate the hydraulic oil to the hydraulic
oil tank through the right center bypass line 40R or the right
parallel line 42R.
[0062] The left center bypass line 40L is a hydraulic oil line
through the control valves 171, 173, 175L, and 176L disposed in the
control valve 17. The right center bypass line 40R is a hydraulic
oil line through the control valves 172, 174, 175R, and 176R
disposed in the control valve 17.
[0063] The control valve 171 is a spool valve that supplies the
hydraulic oil discharged by the left main pump 14L to the left
travelling hydraulic motor 2ML and switches the flow of the
hydraulic oil to discharge the hydraulic oil discharged by the left
travelling hydraulic motor 2ML to the hydraulic oil tank.
[0064] The control valve 172 is a spool valve that supplies the
hydraulic oil discharged by the right main pump 14R to the right
travelling hydraulic motor 2MR and switches the flow of the
hydraulic oil to discharge the hydraulic oil discharged by the
right travelling hydraulic motor 2MR to the hydraulic oil tank.
[0065] The control valve 173 is a spool valve which supplies the
hydraulic oil discharged by the left main pump 14L to the pivot
hydraulic motor 2A and switches the flow of the hydraulic oil to
discharge the hydraulic oil to the hydraulic oil tank.
[0066] The control valve 174 is a spool valve which supplies the
hydraulic oil discharged by the right main pump 14R to the bucket
cylinder 9 and switches the flow of the hydraulic oil to discharge
the hydraulic oil in the bucket cylinder 9 to the hydraulic oil
tank.
[0067] The control valve 175L is a spool valve that switches the
flow of the hydraulic oil to supply the hydraulic oil discharged by
the left main pump 14L to the boom cylinder 7. The control valve
175R is a spool valve that supplies the hydraulic oil discharged by
the right main pump 14R to the boom cylinder 7 and switches the
flow of the hydraulic oil to discharge the hydraulic oil in the
boom cylinder 7 to the hydraulic oil tank.
[0068] The control valve 176L is a spool valve that supplies the
hydraulic oil discharged by the left main pump 14L to the arm
cylinder 8 and switches the flow of the hydraulic oil to discharge
the hydraulic oil in the arm cylinder 8 to the hydraulic oil
tank.
[0069] The control valve 176R is a spool valve that supplies the
hydraulic oil discharged by the right main pump 14R to the arm
cylinder 8 and switches the flow of the hydraulic oil to discharge
the hydraulic oil in the arm cylinder 8 to the hydraulic oil
tank.
[0070] The left parallel line 42L is a hydraulic oil line parallel
to the left center bypass line 40L. When the flow of the hydraulic
oil passing through the left center bypass line 40L is restricted
or interrupted by any of the control valves 171, 173, or 175L, the
left parallel line 42L can supply the hydraulic oil to downstream
control valves. When the flow of the hydraulic oil passing through
the right center bypass line 40R is restricted or interrupted by
any of the control valves 172, 174, or 175R, the right parallel
line 42R is a hydraulic oil line parallel to the right center
bypass line 40R. The right parallel line 42R can supply the
hydraulic oil to downstream control valves.
[0071] The regulator 13 includes a left regulator 13L and a right
regulator 13R. The left regulator 13L controls the discharge amount
of the left main pump 14L by adjusting the swashplate tilt angle of
the left main pump 14L corresponding to the discharge pressure of
the left main pump 14L. Specifically, the left regulator 13L
adjusts the swashplate tilt angle of the left main pump 14L
corresponding to an increase in the discharge pressure of the left
main pump 14L to reduce the discharge amount, for example. The same
applies to the right regulator 13R. This is because the absorbing
horsepower of the main pump 14, which is represented as the product
of the discharge pressure and the discharge amount, is not caused
to exceed the output horsepower of the engine 11.
[0072] The operation device 26 includes a left operation lever 26L,
a right operation lever 26R and a drive lever 26D. The drive lever
26D includes a left drive lever 26DL and a right drive lever
26DR.
[0073] The left operation lever 26L is used for the pivot
operations and the operation of the arm 5. The left operation lever
26L, when it is operated in the forward-backward direction,
utilizes the hydraulic oil discharged by the pilot pump 15 to apply
the control pressure corresponding to the lever operation amount to
a pilot port of the control valve 176. Also, the left operation
lever 26L, when it is operated in the right-left direction,
utilizes the hydraulic oil discharged by the pilot pump 15 to apply
the control pressure corresponding to the lever operation amount to
a pilot port of the control valve 173.
[0074] Specifically, the left operation lever 26L, when it is
operated in the arm closing direction, introduces the hydraulic oil
to a right pilot port of the control valve 176L and introduces the
hydraulic oil to a left pilot port of the control valve 176R. Also,
the left operation lever 26L, when it is operated in the arm
opening direction, introduces the hydraulic oil to a left pilot
port of the control valve 176L and introduces the hydraulic oil to
a right pilot port of the control valve 176R. Also, the left
operation lever 26L, when it is operated in the left pivot
direction, introduces the hydraulic oil to a left pilot port of the
control valve 173 and, when it is operated in the right pivot
direction, introduces the hydraulic oil to a right pilot port of
the control valve 173.
[0075] The right operation lever 26R is used to operate the boom 4
and the bucket 6. The right operation lever 26R, when it is
operated in a forward-backward direction, utilizes the hydraulic
oil discharged by the pilot pump 15 to apply the control pressure
corresponding to the lever operation amount to a pilot port of the
control valve 175. Also, the right operation lever 26R, when it is
operated in the left-right direction, utilizers the hydraulic oil
discharged by the pilot pump 15 to apply the control pressure
corresponding to the lever operation amount to a pilot port of the
control valve 174.
[0076] Specifically, the right operation lever 26R, when it is
operated in the boom down direction, introduces the hydraulic oil
to a right pilot port of the control valve 175R. Also, the right
operation lever 26R, when it is operated in the boom up direction,
introduces the hydraulic oil to a right pilot port of the control
valve 175L and introduces the hydraulic oil to a left pilot port of
the control valve 175R. Also, the right operation lever 26R, when
it is operated in the bucket closing direction, introduces the
hydraulic oil to a left pilot port of the control valve 174 and,
when it is operated in the bucket opening direction, introduces the
hydraulic oil to a right pilot port of the control valve 174.
[0077] The drive lever 26D is used to operate the crawler 10.
Specifically, the left drive lever 26DL is used to operate the left
crawler 1CL. The left drive lever 26DL may be configured to
interlock with a left drive pedal. The left drive lever 26DL, when
it is operated in the forward-backward direction, utilizes the
hydraulic oil discharged by the pilot pump 15 to apply the control
pressure corresponding to the lever operation amount to a pilot
port of the control valve 171. The right drive lever 26DR is used
to operate the right crawler 1CR. The right drive lever 26DR may be
configured to interlock with a right drive pedal. The right drive
lever 26DR, when it is operated in the forward-backward direction,
utilizes the hydraulic oil discharged by the pilot pump 15 to apply
the control pressure corresponding to the lever operation amount to
a pilot port of the control valve 172.
[0078] The discharge pressure sensor 28 includes a discharge
pressure sensor 28L and a discharge pressure sensor 28R. The
discharge pressure sensor 28L detects the discharge pressure of the
left main pump 14L and outputs a detected value to the controller
30. The same applies to the discharge pressure sensor 28R.
[0079] The operation pressure sensor 29 includes operation pressure
sensors 29LA, 29LB, 29RA, 29RB, 29DL, and 29DR. The operation
pressure sensor 29LA detects operational contents of the
forward-backward direction for the left operation lever 26L by an
operator in the form of pressure and outputs the detected value to
the controller 30. The operational contents may be the lever
operation direction and the lever operation amount (lever operation
angle) or the like, for example.
[0080] Similarly, the operation pressure sensor 29LB detects
operational contents of the left-right direction for the left
operation lever 26L by an operator in the form of pressure and
outputs the detected value to the controller 30. The operation
pressure sensor 29RA detects operational contents of the
forward-backward direction for the right operation lever 26R by an
operator in the form of pressure and outputs the detected value to
the controller 30. The operation pressure sensor 29RB detects
operational contents of the left-right direction by an operator for
the right operation lever 26R in the form of pressure and outputs
the detected value to the controller 30. The operation pressure
sensor 29DL detects operational contents of the forward-backward
direction for the left drive lever 26DL by an operator in the form
of pressure and outputs the detected value to the controller 30.
The operation pressure sensor 29DR detects operational contents of
the forward-backward direction for the right drive lever 26DR by an
operator in the form of pressure and outputs the detected value to
the controller 30.
[0081] The controller 30 receives outputs of the operation pressure
sensor 29 and feeds a control command to the regulator 13 as needed
to change the discharge amount of the main pump 14. Also, the
controller 30 receives the outputs of the control pressure sensor
19 provided in the upstream of a throttle 18 and outputs a control
command to the regulator 13 to change the discharge amount of the
main pump 14 as needed. The throttle 18 includes a left throttle
18L and a right throttle 18R, and the control pressure sensor 19
includes a left control pressure sensor 19L and a right control
pressure sensor 19R.
[0082] A left throttle 18L is disposed between the control valve
176L, which is the most downstream, and the hydraulic oil tank in
the left center bypass line 40L. Therefore, the flow of the
hydraulic oil discharged by the left main pump 14L is limited by
the left throttle 18L. The left throttle 18L generates the control
pressure for controlling the left regulator 13L. The left control
pressure sensor 19L is a sensor for detecting the control pressure
and outputs a detected value to the controller 30. The controller
30 controls the discharge amount of the left main pump 14L by
adjusting the swashplate tilt angle of the left main pump 14L
corresponding to the control pressure. The controller 30 decreases
a larger discharge amount of the left main pump 14L as the control
pressure is higher, and increases a larger discharge amount of the
left main pump 14L as the control pressure is lower. The discharge
amount of the right main pump 14R is similarly controlled.
[0083] Specifically, if the hydraulic actuators in the shovel 100
are in a standby state where none of the hydraulic actuators is
operated as shown in FIG. 2, the hydraulic oil discharged by the
left main pump 14L passes through the left center bypass line 40L
and reaches the left throttle 18L. The flow of hydraulic oil
discharged by the left main pump 14L increases the control pressure
generated in the upstream of the left throttle 18L. As a result,
the controller 30 decreases the discharge amount of the left main
pump 14L to an allowable minimum discharge amount to suppress a
pressure loss (pumping loss) caused by the hydraulic oil discharged
by the left main pump 14L passing through the left center bypass
line 40L. On the other hand, if any of the hydraulic actuators is
operated, the hydraulic oil discharged by the left main pump 14L
flows into a to-be-operated hydraulic actuator through a control
valve corresponding to the to-be-operated hydraulic actuator. Then,
the flow of the hydraulic oil discharged by the left main pump 14L
decreases or disappears the amount reaching the left throttle 18L,
thereby lowering the control pressure generated in the upstream of
the left throttle 18L. As a result, the controller 30 increases the
discharge amount of the left main pump 14L and allows an sufficient
amount of the hydraulic oil to flow into the to-be-operated
hydraulic actuator so as to ensure that the to-be-operated
hydraulic actuator can operate. Note that the controller 30
controls the discharge amount of the right main pump 14R in the
same manner.
[0084] According to the arrangement sated above, the hydraulic
system in FIG. 2 can reduce energy consumption wasted for the main
pump 14 in the standby mode. The wasteful energy consumption
includes a pumping loss caused by the hydraulic oil discharged by
the main pump 14 in the center bypass line 40. Also, if a hydraulic
actuator is operated, the hydraulic system in FIG. 2 ensures that a
necessary and sufficient amount of the hydraulic oil can be
supplied from the main pump 14 to the to-be-operated hydraulic
actuator.
[0085] Next, an arrangement for enabling the controller 30 to
automatically operate an actuator by means of a machine control
function is described with reference to FIGS. 3A to 3D. FIGS. 3A to
3D are views of portions of a hydraulic system. Specifically, FIG.
3A is a view of a portion of the hydraulic system related to
operations of the arm cylinder 8, and FIG. 3B is a view of a
portion of the hydraulic system related to operations of the pivot
hydraulic motor 2A. Also, FIG. 3C is a view of a portion of the
hydraulic system related to operations of the boom cylinder 7, and
FIG. 3D is a view of a portion of the hydraulic system related to
operations of the bucket cylinder 9.
[0086] As shown in FIGS. 3A to 3D, the hydraulic system includes a
proportional valve 31 and a shuttle valve 32. The proportional
valve 31 includes proportional valves 31AL to 31DL and 31AR to
31DR, and the shuttle valve 32 includes shuttle valves 32AL to 32DL
and 32AR to 32DR.
[0087] The proportional valve 31 is configured to function as a
machine control valve. The proportional valve 31 is disposed in a
conduit that connects the pilot pump 15 to the shuttle valve 32 and
is configured to cause the flow line area of the conduit to be
variable. In this embodiment, the proportional valve 31 operates in
response to a control command output by the controller 30. Thus,
the controller 30 can supply the hydraulic oil discharged by the
pilot pump 15 to a pilot port of the corresponding control valve in
the control valve 17 via the proportional valve 31 and the shuttle
valve 32, regardless of operator's operations of the operation
device 26.
[0088] The shuttle valve 32 has two inlet ports and one outlet
port. One of the two inlet ports is connected to the operation
device 26, and the other is connected to the proportional valve 31.
The outlet port is connected to the pilot port of the corresponding
control valve in control valve 17. Thus, the shuttle valve 32 can
apply the higher one of the pilot pressure generated by the
operation device 26 and the pilot pressure generated by the
proportional valve 31 to the pilot port of the corresponding
control valve.
[0089] According to this arrangement, even if no operation is
performed on the particular operation device 26, the controller 30
can operate a hydraulic actuator corresponding to the particular
operation device 26.
[0090] For example, as shown in FIG. 3A, the left operation lever
26L is used to operate the arm 5. Specifically, the left operation
lever 26L utilizes the hydraulic oil discharged by the pilot pump
15 to apply the pilot pressure corresponding to operations in the
forward-backward direction to a pilot port of the control valve
176. More specifically, if the left operation lever 26L is operated
in the arm closing direction (backward direction), the left
operation lever 26L applies the pilot pressure corresponding to the
operation amount to a right pilot port of the control valve 176L
and a left pilot port of the control valve 176R. Also, if the left
operation lever 26L is operated in the arm opening direction
(forward direction), the left operation lever 26L applies the pilot
pressure corresponding to the operation amount to a left pilot port
of the control valve 176L and a right pilot port of the control
valve 176R.
[0091] A switch NS is provided to the left operation lever 26L. In
this embodiment, the switch NS is a push-button switch. An operator
can operate the left operation lever 26L with a hand while pushing
the switch NS with a finger. The switch NS may be provided to the
right operation lever 26R or at other positions in the cabin
10.
[0092] The operation pressure sensor 29LA detects operational
contents for the left operation level 26L in the forward-backward
direction by an operator in the form of pressure and outputs the
detected value to the controller 30.
[0093] The proportional valve 31AL operates in response to a
current command fed from the controller 30. Then, the proportional
valve 31AL adjusts the pilot pressure caused by the hydraulic oil
introduced from the pilot pump 15 to a right pilot port of the
control valve 176L and a left pilot port of the control valve 176R
through the proportional valve 31AL and the shuttle valve 32AL. The
proportional valve 31AR operates in response to a current command
fed from the controller 30. Then, the proportional valve 31AR
adjusts the pilot pressure caused by the hydraulic oil introduced
from the pilot pump 15 to a left pilot port of the control valve
176L and a right pilot port of the control valve 176R through the
proportional valve 31AR and the shuttle valve 32AR. The
proportional valve 31AL can adjust the pilot pressure so that the
control valve 176L can be stopped at any valve position. Also, the
proportional valve 31AR can adjust the pilot pressure so that the
control valve 176R can be stopped at any valve position.
[0094] According to this arrangement, the controller 30 can supply
the hydraulic oil discharged by the pilot pump 15 to the right
pilot port of the control valve 176L and the left pilot port of the
control valve 176R through the proportional valve 31AL and the
shuttle valve 32AL, regardless of arm closing operations by an
operator. Namely, the controller 30 can automatically close the arm
5. Also, the controller 30 may supply the hydraulic oil discharged
by the pilot pump 15 to the left pilot port of the control valve
176L and the right pilot port of the control valve 176R through the
proportional valve 31AR and shuttle valve 32AR, regardless of arm
opening operations by the operator. Namely, the controller 30 can
automatically open the arm 5.
[0095] Also, as shown in FIG. 3B, the left operation lever 26L is
used to operate the pivot mechanism 2. Specifically, the left
operation lever 26L utilizes the hydraulic oil discharged by the
pilot pump 15 to apply the pilot pressure corresponding to
operations in the left-right direction to a pilot port of the
control valve 173. More specifically, if the left operation lever
26L is operated in the left turn direction (left direction), the
left operation lever 26L applies the pilot pressure corresponding
to the operation amount to the left pilot port of the control valve
173. Also, if the left operation lever 26L is operated in the right
turn direction (right direction), the left operation lever 26L
applies the pilot pressure corresponding to the operation amount to
the right pilot port of the control valve 173.
[0096] The operation pressure sensor 29LB detects operational
contents for the left operation lever 26L by an operator in the
left-right direction in the form of pressure and outputs the
detected value to the controller 30.
[0097] The proportional valve 31BL operates in response to a
current command fed from the controller 30. Then, the proportional
valve 31BL adjusts the pilot pressure caused by the hydraulic oil
introduced from the pilot pump 15 to the left pilot port of the
control valve 173 through the proportional valve 31BL and shuttle
valve 32BL. The proportional valve 31BR operates in response to a
current command fed from the controller 30. Then, the proportional
valve 31BR adjusts the pilot pressure caused by the hydraulic oil
introduced from the pilot pump 15 to the right pilot port of the
control valve 173 through the proportional valve 31BR and the
shuttle valve 32BR. The proportional valve 31BL and the
proportional valve 31BR can adjust the pilot pressure so that the
control valve 173 can be stopped at any valve position.
[0098] According to this arrangement, the controller 30 can supply
the hydraulic oil discharged by the pilot pump 15 to the left pilot
port of the control valve 173 via the proportional valve 31BL and
shuttle valve 32BL, regardless of the operator's left turn
operation. Namely, the controller 30 can automatically turn the
pivot mechanism 2 to the left direction. Also, the controller 30
may supply the hydraulic oil discharged by the pilot pump 15 to the
right pilot port of the control valve 173 through the proportional
valve 31BR and the shuttle valve 32BR regardless of the operator's
right turn operation. Namely, the controller 30 can automatically
turn the pivot mechanism 2 to the right direction.
[0099] Also, as shown in FIG. 3C, the right operation lever 26R is
used to operate the boom 4. Specifically, the right operation lever
26R utilizes the hydraulic oil discharged by the pilot pump 15 to
apply the pilot pressure corresponding to operations in the
forward-backward direction to the pilot port of the control valve
175. More specifically, if the right operation lever 26R is
operated in the boom up direction (backward direction), the right
operation lever 26R applies the pilot pressure corresponding to the
operation amount to the right pilot port of the control valve 175L
and the left pilot port of the control valve 175R. Also, if the
right operation lever 26R is operated in the boom down direction
(forward direction), the right operation lever 26R applies the
pilot pressure corresponding to the operation amount to the right
pilot port of the control valve 175R.
[0100] The operation pressure sensor 29RA detects operational
contents for the right operation lever 26R by an operator in the
forward-backward operation in the form of pressure and outputs the
detected value to the controller 30.
[0101] The proportional valve 31CL operates in response to a
current command fed from the controller 30. Then, the proportional
valve 31CL adjusts the pilot pressure caused by the hydraulic oil
introduced from the pilot pump 15 to the right pilot port of the
control valve 175L and the left pilot port of the control valve
175R through the proportional valve 31CL and the shuttle valve
32CL. The proportional valve 31CR operates in response to a current
command fed from the controller 30. Then, the proportional valve
31CR adjusts the pilot pressure caused by the hydraulic oil
introduced from the pilot pump 15 to the left pilot port of the
control valve 175L and the right pilot port of the control valve
175R through the proportional valve 31CR and the shuttle valve
32CR. The proportional valve 31CL can adjust the pilot pressure so
that the control valve 175L can be stopped at any valve position.
The proportional valve 31CR can also adjust the pilot pressure so
that the control valve 175R can be stopped at any valve
position.
[0102] According to this arrangement, the controller 30 can supply
the hydraulic oil discharged by the pilot pump 15 to the right
pilot port of the control valve 175L and the left pilot port of the
control valve 175R through the proportional valve 31CL and shuttle
valve 32CL, regardless of operator's boom up operations. Namely,
the controller 30 can automatically raise the boom 4. Also, the
controller 30 can supply the hydraulic oil discharged by the pilot
pump 15 to the right pilot port of the control valve 175R through
the proportional valve 31CR and the shuttle valve 32CR regardless
of operator's boom down operations. Namely, the controller 30 can
automatically lower the boom 4.
[0103] Also, as shown in FIG. 3D, the right operation lever 26R is
used to operate the bucket 6. Specifically, the right operation
lever 26R utilizes the hydraulic oil discharged by the pilot pump
15 to apply the pilot pressure corresponding to operations in the
left-right direction to the pilot port of the control valve 174.
More specifically, if the right operation lever 26R is operated in
the bucket closing direction (left direction), the right operation
lever 26R applies the pilot pressure corresponding to the operation
amount to the left pilot port of the control valve 174. Also, if
the right operation lever 26R is operated in the bucket opening
direction (right direction), the right operation lever 26R applies
the pilot pressure corresponding to the operation amount to the
right pilot port of the control valve 174.
[0104] The operation pressure sensor 29RB detects operational
contents for the right operation lever 26R by an operator in the
left-right direction in the form of pressure and outputs the
detected value to the controller 30.
[0105] The proportional valve 31DL operates in response to a
current command fed from the controller 30. Then, the proportional
valve 31DL adjusts the pilot pressure caused by the hydraulic oil
introduced from the pilot pump 15 to the left pilot port of the
control valve 174 through the proportional valve 31DL and the
shuttle valve 32DL. The proportional valve 31DR operates in
response to a current command fed from the controller 30. Then, the
proportional valve 31DR adjusts the pilot pressure caused by the
hydraulic oil introduced from the pilot pump 15 to the right pilot
port of the control valve 174 through the proportional valve 31DR
and the shuttle valve 32DR. The proportional valves 31DL and 31DR
can adjust the pilot pressure so that the control valve 174 can be
stopped at any valve position.
[0106] According to this arrangement, the controller 30 can supply
the hydraulic oil discharged by the pilot pump 15 to the left pilot
port of the control valve 174 via the proportional valve 31DL and
the shuttle valve 32DL regardless of operator's bucket closing
operations. Namely, the controller 30 can automatically close the
bucket 6. Also, the controller 30 may supply the hydraulic oil
discharged by the pilot pump 15 to the right pilot port of the
control valve 174 through the proportional valve 31DR and the
shuttle valve 32DR, regardless of the operator's bucket opening
operations. Namely, the controller 30 can automatically open the
bucket 6.
[0107] The shovel 100 may be configured to automatically advance
and reverse the lower travelling object 1. In this case, portions
in the hydraulic system related to operations of the left
travelling hydraulic motor 1L and the right travelling hydraulic
motor 1R may be configured in the same way as a portion related to
operations of the boom cylinder 7.
[0108] Next, functions of the controller 30 are described with
reference to FIG. 4. FIG. 4 is a functional block diagram of a
controller 30. In the example of FIG. 4, the controller 30 is
configured to receive signals fed from the posture detection
device, the operation device 26, the object detection device 70,
the capturing device 80 and the switch NS, and the like and perform
various calculations to output control commands to the proportional
valve 31, the display device D1 and the sound output device D2. The
posture detection device may include, for example, a boom angle
sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a body
tilt sensor S4 and a pivot angular velocity sensor S5. The switch
NS includes a recording switch NS1 and an automatic switch NS2. The
controller 30 has a posture recording unit 30A, a trajectory
calculation unit 30B and an autonomous control unit 30C as
functional elements. Each functional element may be arranged with
hardware or software.
[0109] The posture recording unit 30A is configured to record
information regarding the posture of the shovel 100. In this
embodiment, the posture recording unit 30A records the information
regarding the posture of the shovel 100 in the RAM at the timing of
the recording switch NS1 being pressed. Specifically, the posture
recording unit 30A records an output from the posture detection
device every time the recording switch NS1 is pressed. The posture
recording unit 30A may be configured to start the recording when
the recording switch NS1 is pressed at a first time point and to
terminate the recording when the recording switch NS1 is pressed at
a second time point. In this case, the posture recording unit 30A
may repeatedly record the information regarding the posture of the
shovel 100 at a predetermined control cycle spanning from the first
time point to the second time point.
[0110] The trajectory calculation unit 30B is configured to
calculate a target trajectory as a trajectory drawn for a
predetermined portion of the shovel 100 when the shovel 100 is
operated autonomously. The predetermined portion may be, for
example, a predetermined point on the back surface of the bucket 6.
In the present embodiment, the trajectory calculation unit 30B
calculates a target trajectory used when the autonomous control
unit 30C autonomously operates the shovel 100. Specifically, the
trajectory calculation unit 30B calculates the target trajectory
based on the information regarding the posture of the shovel 100
recorded by the posture recording unit 30A.
[0111] The autonomous control unit 30C is configured to operate the
shovel 100 autonomously. In this embodiment, the autonomous control
unit 30C is configured to, if a predetermined activation condition
is satisfied, move a predetermined portion of the shovel 100 along
a target trajectory calculated by the target trajectory unit 30B.
Specifically, the autonomous control unit 30C operates the shovel
100 autonomously so that, when the operation device 26 is operated
during the automatic switch NS2 being pressed, the predetermined
portion of the shovel 100 moves along the target trajectory.
[0112] Next, one exemplary function for the controller 30 to
autonomously control movement of an attachment (which is referred
to as an "autonomous control function" hereinafter) is described
with reference to FIGS. 5 and 6. FIGS. 5 and 6 are block diagrams
of the autonomous control function.
[0113] Initially, the controller 30 generates a bucket target
movement velocity based on an operation tendency and determines the
bucket target movement direction, as shown in FIG. 5. The operation
tendency is determined, for example, based on the lever operation
amount. The bucket target movement velocity is a target value of
the movement velocity of a control reference point in the bucket 6,
and the bucket target movement direction is a target value of the
movement direction of the control reference point in the bucket 6.
The control reference point in the bucket 6 may be a predetermined
point on the back surface of bucket 6, for example. The current
control reference position in FIG. 5 is the current position of the
control reference point and may be calculated based on the boom
angle .beta..sub.1, the arm angle .beta..sub.2 and the pivot angle
.alpha..sub.1. The controller 30 may further utilize the bucket
angle .beta..sub.3 to calculate the current control reference
position.
[0114] Then, the controller 30 calculates three-dimensional
coordinates (Xer, Yer, and Zer) of a control reference position
after passage of the unit time based on the bucket target movement
velocity, the bucket target movement direction and the
three-dimensional coordinates (Xe, Ye, and Ze) of the current
control reference position. The three-dimensional coordinates (Xer,
Yer, Zer) of the control reference position after passage of the
unit time may be, for example, coordinates on the target
trajectory. The unit time may be, for example, a time equal to an
integral multiple of the control cycle. The target trajectory may
be, for example, a target trajectory for a loading operation that
is a work to realize loading of earth and sand into a dump truck.
In this case, the target trajectory may be calculated based on, for
example, the position of the dump truck and an excavation
completion position that is the position of the control reference
point when the excavation operation has been completed. Note that
the position of the dump truck may be calculated based on, for
example, an output of at least one of the object detection device
70 and the capturing device 80, and the excavation completion
position may be calculated based on, for example, an output of the
posture detection device. The excavation completion position may be
calculated based on an output of at least one of the object
detection device 70 and the capturing device 80.
[0115] Then, the controller 30 generates command values
.beta..sub.1r and .beta..sub.2r for rotation of the boom 4 and the
arm 5 and a command values .alpha..sub.1r for pivot of the upper
pivot body 3 based on the calculated three-dimensional coordinates
(Xer, Yer, and Zer). The command value .beta..sub.1r represents the
boom angle .beta..sub.1 when the control reference position has
been aligned to the three-dimensional coordinates (Xer, Yer, and
Zer), for example. Similarly, the command value .beta..sub.2r
represents the arm angle .beta..sub.2 when the control reference
position has been aligned to the three-dimensional coordinates
(Xer, Yer, and Zer), and the command value .alpha..sub.1r
represents the pivot angle .alpha..sub.1 when the control reference
position has been aligned to the three-dimensional coordinates
(Xer, Yer, and Zer).
[0116] Then, as shown in FIG. 6, the controller 30 operates the
boom cylinder 7, the arm cylinder 8 and the pivot hydraulic motor
2A so that the boom angle .beta..sub.1, the arm angle .beta..sub.2
and the pivot angle .alpha..sub.1 are equal to the generated
command values .beta..sub.1r, .beta..sub.2r and .alpha..sub.1r,
respectively. Note that the pivot angle .alpha..sub.1 is calculated
based on an output of the pivot angular velocity sensor S5, for
example.
[0117] Specifically, the controller 30 generates a boom cylinder
pilot pressure command corresponding to the difference
.DELTA..beta..sub.1 between the current value of the boom angle
.beta..sub.1 and the command value .beta..sub.1r. Then, a control
current corresponding to the boom cylinder pilot pressure command
is fed to the boom control mechanism 31C. The boom control
mechanism 31C is configured so that the pilot pressure
corresponding to the control current corresponding to the boom
cylinder pilot pressure command can be applied to the control valve
175 as the boom control valve. The boom control mechanism 31C may
be, for example, the proportional valve 31CL and the proportional
valve 31CR in FIG. 3C.
[0118] Then, upon receiving the pilot pressure generated by the
boom control mechanism 31C, the control valve 175 causes the
hydraulic oil discharged by the main pump 14 to flow into the boom
cylinder 7 in a flow direction and a flow amount corresponding to
the pilot pressure.
[0119] At this time, the controller 30 may generate a boom spool
control command based on a spool displacement amount of the control
valve 175 detected by a boom spool displacement sensor S7. The boom
spool displacement sensor S7 is a sensor that detects the
displacement amount of the spool constituting the control valve
175. The controller 30 may feed a control current corresponding to
a boom spool control command to the boom control mechanism 31C. In
this case, the boom control mechanism 31C applies the pilot
pressure corresponding to the control current corresponding to the
boom spool control command to the control valve 175.
[0120] The boom cylinder 7 extends or contracts by the hydraulic
oil supplied through the control valve 175. The boom angle sensor
S1 detects the boom angle .beta..sub.1 of the boom 4 driven by the
expanding or contracting boom cylinder 7.
[0121] Then, the controller 30 feeds back the boom angle
.beta..sub.1 detected by the boom angle sensor S1 as the current
value of the boom angle .beta..sub.1 used to generate the boom
cylinder pilot pressure command.
[0122] The above description relates to the operation of the boom 4
based on the command value .beta..sub.1r but it is equally
applicable to the operation of the arm 5 based on the command value
.beta..sub.2r and the pivot operation of the upper pivot body 3
based on the command value .alpha..sub.1r. The arm control
mechanism 31A is configured so that the pilot pressure
corresponding to the control current corresponding to the arm
cylinder pilot pressure command can be applied to the control valve
176 serving as the arm control valve. The arm control mechanism 31A
may be, for example, the proportional valve 31AL and the
proportional valve 31AR in FIG. 3A. In addition, the pivot control
mechanism 31B is configured so that the pilot pressure
corresponding to the control current corresponding to the pivot
hydraulic motor pilot pressure command can be applied to the
control valve 173 serving as a pivot control valve. The pivot
control mechanism 31B may be, for example, the proportional valve
31BL and the proportional valve 31BR in FIG. 3B. Also, the arm
spool displacement sensor S8 is a sensor for detecting the
displacement amount of the spool constituting the control valve
176, and the pivot spool displacement sensor S2A is a sensor for
detecting the displacement amount of the spool constituting the
control valve 173.
[0123] As shown in FIG. 5, the controller 30 may use pump discharge
amount deriving units CP1, CP2 and CP3 to derive the pump discharge
amount from the command values .beta..sub.1r, .beta..sub.2r and
.alpha..sub.1r. In this embodiment, the pump discharge amount
deriving unit CP1, CP2 and CP3 uses a preregistered reference table
or the like to derive the pump discharge amount from the command
values .beta..sub.1r, .beta..sub.2r and .alpha..sub.1r. The pump
discharge amounts derived by the pump discharge deriving units CP1,
CP2 and CP3 are summed and are fed to a pump flow calculation unit
as the total pump discharge amount. The pump flow calculation unit
controls the discharge amount of the main pump 14 based on the
incoming total pump discharge amount. In this embodiment, the pump
flow calculation unit controls the discharge amount of the main
pump 14 by changing the swashplate tilt angle of the main pump 14
corresponding to the total pump discharge amount.
[0124] In this manner, the controller 30 can simultaneously perform
the opening control of the control valve 175 as the boom control
valve, the control valve 176 as the arm control valve and the
control valve 173 as the pivot control valve and the control of the
discharge amount of the main pump 14. Thus, the controller 30 can
supply an appropriate amount of the hydraulic oil to each of the
boom cylinder 7, the arm cylinder 8 and the pivot hydraulic motor
2A.
[0125] Also, the controller 30 performs the autonomous control by
calculating the three-dimensional coordinates (Xer, Yer, and Zer),
generating the command values .beta..sub.1r, .beta..sub.2r and
.alpha..sub.1r, determining the discharge amount of the main pump
14 as one control cycle, and repeating the control cycle. Also, the
controller 30 can improve the accuracy of the autonomous control by
performing feedback control on a control reference position based
on respective outputs of the boom angle sensor S1, the arm angle
sensor S2 and the pivot angle sensor S5. Specifically, the
controller 30 can improve the accuracy of the autonomous control by
controlling the flow amount of the hydraulic oil flowing into each
of the boom cylinder 7, the arm cylinder 8 and the pivot hydraulic
motor 2A. Note that the controller 30 may similarly control the
flow amount of the hydraulic oil flowing into the bucket cylinder
9.
[0126] An operation performed by an operator of the shovel 100 to
set a target trajectory is described with reference to FIGS. 7A and
7B. FIGS. 7A and 7B illustrate one exemplary aspect of a work site
where earth and sand are loaded into a dump truck DT by a shovel
100. Specifically, FIG. 7A is a top view of the work site. FIG. 7B
is a view of the work site viewed from the direction indicated by
the arrow AR1 in FIG. 7A. In FIG. 7B, the shovel 100 (except the
bucket 6) is not shown for clarity. Also, in FIG. 7A, the shovel
100 drawn as a solid line represents the state of the shovel 100 at
completion of an excavation operation, the shovel 100 drawn as a
dashed line represents the state of the shovel 100 during a
compound operation, and the shovel 100 drawn as a dotted line
represents the state of the shovel 100 before the start of an earth
removal operation.
[0127] Similarly, in FIG. 7B, the bucket 6A drawn as a solid line
represents the state of the bucket 6 at completion of the
excavation operation, the bucket 6B drawn as a dashed line
represents the state of the bucket 6 during the compound operation,
and the bucket 6C drawn as a dotted line represents the state of
the bucket 6 before the start of the earth removal operation. Also,
the thick dashed lines in FIGS. 7A and 7B represent trajectories of
a predetermined point on the back surface of the bucket 6.
[0128] The operator pushes the recording switch NS1 at completion
of the excavation operation to record the posture of the shovel 100
at a start position of the compound operation including a right
pivot operation in a RAM. Specifically, an output of the posture
detection device when a predetermined point (control reference
point) on the back surface of the bucket 6 is at point P1 is
recorded in the RAM. The controller 30 may record the point 21
serving as the excavation completion position as the start position
of the compound operation including a pivot operation.
[0129] Then, the operator uses the operation device 26 to perform
the compound operation. In this embodiment, the operator performs
the compound operation including a right pivot operation.
Specifically, the compound operation including at least one of a
boom up operation and an arm closing operation and a right pivot
operation is performed until the posture of the shovel 100 becomes
one as shown by a dashed line, that is, until the predetermined
point on the back surface of the bucket 6 reaches point P2. The
compound operation may include an opening-closing operation for the
bucket 6. This is to move the bucket 6 above the dump platform
while preventing contact between the platform of the dump truck DT
having the height Hd and the bucket 6.
[0130] Then, the operator performs the compound operation including
an arm opening operation and a right pivot operation until the
posture of the shovel 100 becomes one as shown by a dotted line,
that is, until the predetermined point on the back surface of the
bucket 6 reaches point P3. The compound operation may include at
least one of an operation of the boom 4 and an opening-closing
operation of the bucket 6. This is to allow soil such as earth and
sand to be removed from the front side (operator's seat side) of
the platform of the dump truck DT.
[0131] Then, the operator pushes the recording switch NS1 before
the start of the earth removal operation to record the posture of
the shovel 100 at the completion position of the compound operation
in the RAM. Specifically, an output of the posture detection device
when the predetermined point on the back surface of the bucket 6 is
at point P3 is recorded in the RAM. The controller 30 may record
the point P3 serving as the dump (earth removal) start position as
the completion position of the compound operation.
[0132] By performing the above-stated sequence of operations, the
operator of the shovel 100 can cause the controller 30 to calculate
the target trajectory for loading into the dump truck DT by the
shovel 100.
[0133] Next, an operation (referred to as a "calculation operation"
hereinafter) for the controller 30 to calculate the target
trajectory related to the loading operation is described with
reference to FIG. 8. FIG. 8 is a flowchart for illustrating one
exemplary calculation operation. The controller 30 performs this
calculation operation at a predetermined control cycle repeatedly,
for example, until the target trajectory is calculated.
[0134] First, the controller 30 determines whether the recording
switch NS1 is pressed (step ST1). The controller 30 performs this
determination repeatedly until the operator presses the recording
switch NS1 at the start position of the compound operation
including a right pivot operation, for example.
[0135] If it is determined that the recording switch NS1 is pressed
(YES in step ST1), the posture recording unit 30A of the controller
30 records the posture of the shovel 100 at the start position of
the compound operation (step ST2). In this embodiment, the posture
recording unit 30A records the information regarding the posture of
the shovel 100 shown by a solid line in FIG. 7A by recording an
output of the posture detection device.
[0136] Then, the controller 30 determines whether the recording
switch NS1 is pressed (step ST3). The controller 30 performs this
determination repeatedly until the operator presses the recording
switch NS1 at the completion position of the compound operation,
for example.
[0137] If it is determined that the recording switch NS1 is pressed
(YES in step ST3), the posture recording unit 30A records the
posture of the shovel 100 at the completion position of the
compound operation (step ST4). In this embodiment, the posture
recording unit 30A records the information regarding the posture of
the shovel 100 shown by a dashed line in FIG. 7A by recording an
output of the posture detection device.
[0138] The controller 30 may record an operating velocity of the
compound operation. If the work area is narrow, the operator may
feel that the operating velocity of the boom up operation relative
to the pivot operation is high. Also, if the operator is not
familiar with operations of the shovel 100, the operator may feel
that the operating velocity of the boom up operation relative to
the pivot operation is high. Accordingly, the controller 30 may be
configured to record the operating velocity pattern of the compound
operation so as to adjust the operating velocity in the autonomous
control in accordance with differences of work sites or operators'
skills. According to this arrangement, the controller 30 can reduce
the operating velocity so as not to cause the operator to feel that
the operating velocity is high, for example.
[0139] The posture recording unit 30A may repeatedly record outputs
of the posture detection device in a predetermined control cycle
after the recording switch NS1 is pressed at the start position of
the compound operation and before the recording switch NS1 is
pressed at the completion position of the compound operation. In
this case, the posture recording unit 30A may inform the operator
that the recording is in progress so that the operator can
recognize that the information regarding the posture of the shovel
100 is being continuously recorded. For example, the posture
recording unit 30A may display the fact that the recording is in
progress on the display device D1 and may output voice information
for indicating this fact from the sound output device D2.
[0140] Then, the trajectory calculation unit 30B of the controller
30 calculates the target trajectory (step ST5). In this embodiment,
the trajectory calculation unit 30B calculates the target
trajectory for the loading operation based on the information
regarding the posture of the shovel 100 recorded at the start
position of the compound operation and the information regarding
the posture of the shovel 100 recorded at the completion position
of the compound operation. The trajectory calculation unit 30B may
calculate the target trajectory based on the sequence of
information regarding the posture of the shovel 100 from the start
position to the completion position of the compound operation.
[0141] The trajectory calculation unit 30B may calculate the target
trajectory by further taking information regarding the dump truck
DT into consideration. The information regarding the dump truck DT
may be at least one of the height of the bed of the dump truck DT,
the orientation of the dump truck DT, the size of the dump truck
DT, and the type of dump truck DT or the like, for example. The
information regarding the dump truck DT may be acquired using at
least one of the object detection device 70 and the capturing
device 80, for example. The controller 30 may acquire the
information regarding the dump truck DT through at least one of a
positioning device, a communication device, or the like.
[0142] Then, the controller 30 broadcasts completion of the
calculation of the target trajectory (step ST6). In this
embodiment, the trajectory calculation unit 30B displays
information on the display device D1 for indicating that the
calculation of the target trajectory for the loading work has been
completed. The trajectory calculation unit 30B may output voice
information for indicating completion of the calculation from the
sound output device D2.
[0143] Upon calculating the target trajectory, the controller 30
can autonomously operate the shovel 100 so that a predetermined
portion of the shovel 100 moves along the target trajectory.
[0144] The controller 30 may perform the autonomous control based
on the recorded operating velocity pattern for the compound
operation. In this case, the controller 30 can perform optimal
autonomous control based on the operating velocity pattern
corresponding to differences of work sites or operators'
skills.
[0145] Next, an operation for the controller 30 to cause the shovel
100 to autonomously operate (referred to as an "autonomous
operation" hereinafter) is described with reference to FIG. 9. FIG.
9 is a flowchart for illustrating one exemplary autonomous
operation.
[0146] First, the autonomous control unit 30C of the controller 30
determines whether an activation condition of the autonomous
control is satisfied (step ST11). In this embodiment, the
autonomous control unit 30C determines whether the activation
condition of the autonomous control for loading work is
satisfied.
[0147] The activation condition may include a first activation
condition and a second activation condition, for example. The first
activation condition may be that "the target trajectory for loading
work has already been calculated", for example. The second
activation condition may be that "a pivot operation has been
performed while the automatic switch NS2 is pressed", for example.
In the example shown in FIGS. 7A and 7B, the "pivot operation" in
the second activation condition may be a "right pivot operation."
In this case, in the example shown in FIGS. 7A and 7B, even if a
left pivot operation is performed while the automatic switch NS2 is
pressed, the activation condition is not met. However, the second
activation condition may be that "the automatic switch NS2 is
pressed." In this case, the activation condition is satisfied
regardless of the presence of the pivot operation. Alternatively,
the second activation condition may be "the automatic switch NS2 is
pressed while the left operation lever 26L is retained in a neutral
position." In this case, even in the state where the automatic
switch NS2 is pressed, when the left operation lever 26L is
operated, the activation condition is not met.
[0148] If it is determined that the activation condition is
satisfied (YES in step ST11), the autonomous control unit 30C
starts the autonomous control (step ST12). In this embodiment, the
autonomous control unit 30C automatically raises the boom 4 in
accordance with the right pivot operation through a manual
operation so that the trajectory drawn by a predetermined point on
the back surface of the bucket 6 is along the target trajectory. In
this case, the larger the right pivot velocity by the manual
operation is, the higher the up velocity of the boom 4 by the
autonomous control is. The autonomous control unit 30C may increase
or decrease the bucket angle .beta..sub.3 to retain the posture of
the bucket 6 so that soil or the like caught into the bucket 6 is
not caused to fall.
[0149] The autonomous control unit 30C may inform an operator that
the autonomous control is in progress. For example, the autonomous
control unit 30C may display the fact that the autonomous control
is in progress on the display device D1 and may output voice
information indicating this fact from the sound output device
D2.
[0150] Then, the autonomous control unit 30C determines whether the
autonomous control completion condition is satisfied (step ST13).
In this embodiment, the autonomous control unit 30C determines
whether the autonomous control completion condition for loading
work is satisfied.
[0151] The completion condition includes, for example, a first
completion condition and a second completion condition. The first
completion condition is that "a predetermined part of the shovel
100 has reached a completion position", for example. If the second
activation condition is that "a pivot operation is performed while
the automatic switch NS2 is pressed", the second completion
condition is that "pressing the automatic switch NS2 is stopped" or
"the pivot operation is stopped". Also, if the second activation
condition is that "the automatic switch NS2 is pressed", the second
completion condition is that "the automatic switch NS2 is pressed
again", for example. Alternatively, if the second activation
condition is that "the automatic switch NS2 is pressed while the
left operation lever 26L is retained at a neutral position", the
second completion condition is that "pressing the automatic switch
NS2 is stopped" or "the pivot operation is performed."
[0152] If it is determined that the completion condition is
satisfied (YES in step ST13), the autonomous control unit 30C
terminates the autonomous control (step ST14). In this embodiment,
the autonomous control unit 30C determines that if the first or
second completion condition is satisfied, the completion condition
is satisfied, and stops all movements of an actuator that are not
based on the manual operation.
[0153] The autonomous control unit 30C may informs an operator that
the autonomous control has been terminated. For example, the
autonomous control unit 30C may display the fact that the
autonomous control has been terminated on the display device D1 and
may output voice information indicating this fact from the sound
output device D2.
[0154] Then, the operator performs a manually operated earth
removal operation to discharge the earth and sand in the bucket 6
to the platform of the dump truck DT. Then, the operator performs a
manually operated boom down pivot to restore the posture of an
excavation attachment AT to the posture where the excavation
operation is possible. Then, the operator restarts the autonomous
control after the manually operated excavation operation is
performed and new earth and sand or the like have been caught in
the bucket 6, and changes the posture of the excavation attachment
AT into the posture where the excavation operation is possible. The
operator can complete the loading work by repeating these
operations.
[0155] Next, the loading of earth and sand into the dump truck DT
by means of the shovel 100 executing the autonomous control is
described with reference to FIGS. 10A to 10C. FIGS. 10A to 10C are
top views of a work site.
[0156] FIG. 10A shows a state where a first manually operated boom
up pivot operation has been completed. The boom up pivot operation
may include at least one of an arm opening operation, an arm
closing operation, a bucket opening operation and a bucket closing
operation. A dashed line in FIG. 10A represents the posture of the
shovel 100 after completion of a first manually operated excavation
operation is completed and before start of a first manually
operated boom up pivot operation. Range R1 indicates a range on the
platform of the dump truck DT in where the earth and sand are
loaded by a manually operated earth removal operation after the
first boom up pivot operation.
[0157] FIG. 10B shows a state where a second boom up pivot
operation in the autonomous control has been completed. A dashed
line in FIG. 10B represents the posture of the shovel 100 after
completion of a second manually operated excavation operation and
before start of a second manually operated boom up pivot operation.
Range R2 indicates a range on the platform of the dump truck DT in
where the earth and sand are loaded by a manually operated earth
removal operation after the second boom up pivot operation.
[0158] FIG. 10C shows a state where a third boom up pivot operation
in the autonomous control has been completed. A dashed line in FIG.
10C represents the posture of the shovel 100 after completion of a
third manually operated excavation operation and before start of a
third manually operated boom up pivot operation. Range R3 indicates
a range on the platform of the dump truck DT in where the earth and
sand are loaded by a manually operated earth removal operation
after the third boom up pivot operation.
[0159] The operator of the shovel 100 pushes the recording switch
NS1 at the time point before the start of the manually operated
first boom up pivot operation, that is, at a first time point where
the state of the shovel 100 is changed into one indicated in the
dotted line in FIG. 10A, to record the information regarding the
posture of the shovel 100 at the start position of the compound
operation including a pivot operation. Then, the operator performs
the compound operation including the boom up operation and the
right pivot operation and pushes the recording switch NS1 at a
second time point where the state of the shovel 100 is changed into
one shown in a solid line in FIG. 10A to record the information
regarding the posture of the shovel 100 at the completion position
of the compound operation including the pivot operation.
[0160] The controller 30 calculates the target trajectory available
for the second and subsequent boom up pivot operations in the
autonomous control based on the information regarding the posture
of the shovel 100 recorded at the first and second time points.
[0161] After performing the first earth removal operation, the
operator manually performs a boom down pivot operation to bring the
bucket 6 close to mound F1 shown in FIG. 10A. Then, the operator
manually performs an excavation operation to catch the earth and
sand or the like forming the mound F1 in the bucket 6. Then, the
operator pushes the automatic switch NS2 at a third time point,
where the state of the shovel 100 is changed into one shown in a
dotted line in FIG. 10B, to activate the second boom up pivot
operation in the autonomous operation rather than the manual
operation.
[0162] The controller 30 uses the target trajectory calculated at
the second time point to perform the second boom up pivot operation
in the autonomous control. Specifically, the controller 30
automatically pivots the pivot mechanism 2 in the right direction
and automatically lifts the boom 4 so that the trajectory drawn
with a predetermined point on the back surface of the bucket 6 is
aligned with the target trajectory. In this embodiment, the end
position of the target trajectory is set such that the
predetermined point on the back surface of the bucket 6 comes
directly above the center point of the range R2. This is because a
to-be-loaded object such as the earth and sand is loaded in the
order from the inner side of the platform of the dump truck DT (the
side close to a front panel or an cab of the dump truck DT) to the
front side (the side away from the front panel or the cab of the
dump truck DT). However, the end position of the target trajectory
may be set by adding a predetermined correction value to the first
end position. In this case, the correction value may be set in
advance. For example, the correction value may be set to a value
corresponding to the bucket size. This is because the earth and
sand or the like in the bucket 6 can be caused to be discharged to
the range R2 at the completion time point of the second boom up
pivot operation only through the operator's bucket opening
operation. In this case, the end position of the target trajectory
may be calculated based on at least one of the information
regarding the bucket 6 such as the volume of the bucket 6 and the
information regarding the dump truck DT. However, the end position
of the target trajectory may be the same as the end position of the
trajectory of the first manually operated boom up pivot operation.
In other words, the end position of the target trajectory may be
the position of a predetermined point on the back surface of the
bucket 6 when the recording switch NS1 is pushed at the second time
point.
[0163] After completion of the second boom up pivot operation, the
operator performs the second earth removal operation in a manual
operation. In this embodiment, the operator can discharge the earth
and sand or the like in the bucket 6 to the range R2 by only
performing a bucket opening operation.
[0164] After performing the second earth removal operation, the
operator performs the boom down pivot operation manually to bring
the bucket 6 close to the embankment F2 shown in FIG. 10B. Then,
the operator performs an excavation operation manually to catch the
earth and sand or the like forming the mound F2. Then, the operator
pushes the automatic switch NS2 at a time point of completion of
the excavation operation, that is, at the fourth time point where
the state of the shovel 100 is changed into one shown in a dotted
line in FIG. 10C, to start the third boom up pivot operation in the
autonomous control.
[0165] The controller 30 uses the target trajectory calculated at
the second time point to perform the third boom up pivot operation
in the autonomous control. Specifically, the controller 30
automatically pivots the pivot mechanism 2 in the right direction
and automatically lifts the boom 4 so that the trajectory drawn by
a predetermined point on the back surface of the bucket 6 can be
aligned with the target trajectory. In this embodiment, the end
position of the target trajectory is set such that the
predetermined point on the back surface of the bucket 6 comes
directly above the center point of the range R3. This is because
the earth and sand or the like in the bucket 6 can be caused to be
discharged to the range R3 only through the operator's bucket
opening operation at the completion time point of the third boom up
pivot operation.
[0166] After completion of the third boom up pivot operation, the
operator performs the third earth removal operation manually. In
this embodiment, the operator can discharge the earth and sand or
the like in the bucket 6 to the range R3 on the platform of the
dump truck DT by only performing the bucket opening operation.
[0167] As stated above, the operator of the shovel 100 can perform
only the first boom up pivot operation for the single dump truck DT
manually to cause the shovel 100 to autonomously perform the second
and subsequent boom up pivot operations.
[0168] Also, in this embodiment, the controller 30 is configured to
change the end position of the target trajectory for each boom up
pivot operation in the autonomous control based on the information
regarding the dump truck DT. Accordingly, the operator of the
shovel 100 can only perform the bucket opening operation whenever
the boom up pivot operation is finished in the autonomous control
to discharge the earth and sand or the like to an appropriate place
of the platform of the dump truck DT.
[0169] Next, one exemplary image displayed during execution of the
autonomous control is described with reference to FIG. 11. As shown
in FIG. 11, the image Gx displayed on the display device D1
includes a time display unit 411, a rotation rate mode display unit
412, a drive mode display unit 413, an attachment display unit 414,
an engine control state display unit 415, an urea water remaining
amount display unit 416, a fuel remaining amount display unit 417,
a cooling water temperature display unit 418, an engine operating
time display unit 419, a camera image display unit 420, and a work
state display unit 430. The rotation rate mode display unit 412,
the drive mode display unit 413, the attachment display unit 414,
and the engine control state display unit 415 are display units
that display information regarding the setting state of the shovel
100. The urea water remaining amount display unit 416, the fuel
remaining amount display unit 417, the cooling water temperature
display unit 418, and the engine operating time display unit 419
are display units that display information regarding the operation
state of the shovel 100. The images displayed on respective
portions are generated by the display device D1 using various types
of data transmitted from the controller 30, image data transmitted
from the capturing device 80 or the like.
[0170] The time display unit 411 displays the current time. The
rotation rate mode display unit 412 displays the rotation rate mode
set by an engine rotation rate adjustment dial (not shown) as
operation information of the shovel 100. The drive mode display
unit 413 displays the drive mode as the operation information of
the shovel 100. The drive mode indicates the setting condition of
the travelling hydraulic motor using a variable capacity motor. For
example, the drive mode has a low speed mode and a high speed mode,
in the low speed mode, a mark representing a "tortoise" is
displayed, and in the high speed mode, a mark representing a
"rabbit" is displayed. The attachment display unit 414 is an area
for displaying an icon representing the type of the currently
mounted attachment. The engine control state display unit 415
displays the control state of the engine 11 as the operation
information of the shovel 100. In the example of FIG. 11, the
"automatic deceleration and automatic stop mode" is selected as the
operation state of the engine 11. The "automatic deceleration and
automatic stop mode" means a control state where the engine
rotation rate is automatically reduced and the engine 11 is
automatically stopped depending on the duration of the
non-operation state. Other control states of the engine 11 include
"automatic deceleration mode", "automatic stop mode" and "manual
deceleration mode".
[0171] The urea water remaining amount display unit 416 displays
the remaining amount state of urea water stored in an urea water
tank as the operation information of the shovel 100. In the example
of FIG. 11, the urea water remaining amount display unit 416
displays a bar gauge representing the current remaining amount
state of the urea water. The remaining amount of urea water is
displayed based on the data fed from an urea water level sensor
provided in the urea water tank.
[0172] The fuel remaining amount display unit 417 displays the
remaining amount of fuel stored in a fuel tank as operation
information. In the example of FIG. 11, the fuel remaining amount
display unit 417 displays a bar gauge representing the current fuel
remaining amount state. The remaining amount of fuel is displayed
based on data fed from a fuel remaining amount sensor provided in
the fuel tank.
[0173] The cooling water temperature display unit 418 displays the
temperature condition of the engine cooling water as the operation
information of the shovel 100. In the example of FIG. 11, a bar
gauge representing the temperature condition of the engine cooling
water is displayed in the cooling water temperature display unit
418. The temperature of the engine cooling water is indicated based
on data fed from a water temperature sensor provided in engine
11.
[0174] The engine operation time display unit 419 displays the
accumulated operation time of the engine 11 as the operation
information of the shovel 100. In the example of FIG. 11, the
engine operation time display unit 419 displays the accumulated
operation time since a counter was restarted by the operator along
with the unit "hr (time)". The engine operation time display unit
419 may display the lifetime operation time of the entire period
after the shovel was manufactured or the interval operation time
since the counter was restarted by the operator.
[0175] The camera image display unit 420 displays an image captured
by the capturing device 80. In the example of FIG. 11, an image
taken by a rear camera 80B mounted on a rear end of the top surface
of the upper pivot body 3 is displayed on the camera image display
unit 420. The camera image display unit 420 may display a camera
image captured by a left camera 80L mounted to a left end of the
top surface of the upper pivot body 3 or a right camera 80R mounted
to a right end of the top surface. The camera image display unit
420 may display images captured by a plurality of cameras of the
left camera 80L, the right camera 80R and the rear camera 80B such
that the images are in line. Also, the camera image display unit
420 may display a composite image of the plurality of camera images
captured by at least two of the left camera 80L, the right camera
80R and the rear camera 80B. For example, the composite image may
be a bird's-eye image.
[0176] Each camera may be positioned so that a portion of the upper
pivot body 3 can be included in the camera image. By including a
portion of the upper pivot body 3 in the displayed image, the
operator can easily understand the distance between an object
displayed on the camera image display unit 420 and the shovel 100.
In the example of FIG. 11, the camera image display unit 420
displays an image of a counterweight 3w of the upper pivot body
3.
[0177] The camera image display unit 420 displays a FIG. 421
representing the direction of the capturing device 80 that has
captured the displayed camera image. The FIG. 421 is composed of a
shovel FIG. 421a representing the shape of the shovel 100 and a
band-shaped directional indication shape 421b representing the
capturing direction of the capturing device 80 that has captured
the displayed camera image. The FIG. 421 is a display unit that
displays information regarding the setting state of the shovel
100.
[0178] In the example of FIG. 11, the directional indication FIG.
421b is displayed on the underside of the shovel FIG. 421a (in the
opposite side to the figure representing the excavation attachment
AT). This indicates that a rear image of the shovel 100 captured by
the rear camera 80B is displayed on the camera image display unit
420. For example, if an image captured by the right camera 80R is
displayed on the camera image display unit 420, the directional
indication FIG. 421b is displayed on the right side of the shovel
FIG. 421a. Also, for example, if an image captured by the left
camera 80L is displayed on the camera image display unit 420, the
directional indication FIG. 421b is displayed on the left side of
the shovel FIG. 421a.
[0179] For example, the operator can push an image selector switch
(not shown) provided in the cabin 10 to switch the image displayed
on the camera image display unit 420 to an image or the like
captured by another camera.
[0180] If the shovel 100 is not provided with the capturing device
80, different information may be displayed instead of the camera
image display unit 420.
[0181] The work state display unit 430 displays the work state of
the shovel 100. In the example of FIG. 11, the work state display
unit 430 includes a FIG. 431 of the shovel 100, a FIG. 432 of the
dump truck DT, a FIG. 433 representing the state of the shovel 100,
a FIG. 434 representing the completion position of the excavation,
a FIG. 435 representing the target trajectory, a figure
representing the start of the earth removal, a FIG. 436
representing the start position of the earth removal, and a FIG.
437 of the earth and sand already loaded on the platform of the
dump truck DT. The FIG. 431 shows the state of shovel 100 when the
shovel 100 is viewed from the top. The FIG. 432 shows the state of
the dump truck DT when the dump truck DT is viewed from above. The
FIG. 433 is a text message representing the state of the shovel
100. The FIG. 434 shows the state of the bucket 6 after completion
of the excavation operation when the bucket 6 is viewed from the
top. The FIG. 435 shows the top view of the target trajectory. The
FIG. 436 shows the state of the bucket 6 when the earth removal
operation is started, that is, when the bucket 6 at the end
position of the target trajectory is viewed. The FIG. 437 shows the
state of earth and sand already loaded onto the platform of the
dump truck DT.
[0182] The controller 30 may be configured to generate the FIGS.
431 to 436 based on the information regarding the posture of the
shovel 100 and the information regarding the dump truck DT and the
like. Specifically, the FIG. 431 may be generated to represent the
actual posture of the shovel 100, and the FIG. 432 may be generated
to represent the actual orientation and size of the dump truck DT.
Also, the FIG. 434 may be generated based on the information
recorded by the posture recording unit 30A, and the FIGS. 435 and
436 may be generated based on the information calculated by the
trajectory calculation unit 30B. Also, the controller 30 may detect
the state of earth and sand already loaded onto the platform of the
dump truck DT based on the output of at least one of the object
detection device 70 and the capturing device 80 and change the
position and size of the FIG. 437 depending on the detected
state.
[0183] The controller 30 may also display the current number of
boom up pivot operations of the dump truck DT, the number of boom
up pivot operations by the autonomous control, the weight of the
earth and sand loaded on the dump truck DT, and the ratio of the
weight of the earth and sand loaded on the dump truck DT to the
maximum load weight on the work state display unit 430.
[0184] According to this arrangement, the operator of the shovel
100 can view the image Gx to determine whether the autonomous
control is performed. Also, by viewing the image Gx including the
FIG. 431 of the shovel 100 and the FIG. 432 of the dump truck DT,
the operator can easily grasp the relative positional relationship
of the shovel 100 and the dump truck DT. In addition, by viewing
the image Gx including the FIG. 435 representing the target
trajectory, the operator can easily understand the set target
trajectory. In addition, by viewing the image Gx including the FIG.
434, which is information regarding the excavation completion
position serving as the start position of the boom up pivot
operation, the operator can easily grasp the state when the boom up
pivot operation is started. In addition, by viewing the image Gx
including the FIG. 436, which is information regarding the earth
removal start position that is the completion position of the boom
up pivot operation, the operator can easily grasp the state when
the boom up pivot operation is finished.
[0185] As stated above, the shovel 100 according to an embodiment
of the present invention includes a lower travelling body 1, an
upper pivot body 3 pivotably mounted to the lower travelling body
1, an excavation attachment AT as an attachment rotatably mounted
to the upper pivot body 3, and the controller 30 serving as a
control device provided to the upper pivot body 3. The controller
30 is configured to autonomously perform a compound operation
including operations of excavation attachment AT and the pivot
operation. According to this arrangement, the shovel 100 can
autonomously perform the compound operation including the pivot
operation in accordance with the operator's intention.
[0186] The compound operation including the pivot operation may be
a boom up pivot operation, for example. The target trajectory for
the boom up pivot operation is calculated based on the information
recorded during the manually operated boom up pivot operation, for
example. However, the target trajectory for the boom up pivot
operation may be calculated based on the information recorded
during the manually operated boom down pivot operation. Also, the
compound operation including the pivot operation may be a boom down
pivot operation. The target trajectory for the boom down pivot
operation is calculated based on the information recorded during
the manually operated boom down pivot operation, for example.
However, the target trajectory for the boom down pivot operation
may be calculated based on the information recorded during the
manually operated boom up pivot operation. The compound operation
including the pivot operation may also be another repetitive
operation including the pivot operation.
[0187] The shovel 100 may include a posture detection device for
obtaining information regarding the orientation of the excavation
attachment AT. The posture detection device may include, for
example, at least one of a boom angle sensor S1, an arm angle
sensor S2, a bucket angle sensor S3, a body tilt sensor S4, and a
pivot angular velocity sensor S5. The controller 30 may be
configured to calculate a target trajectory drawn by a
predetermined point in the excavation attachment AT based on the
information acquired by the posture detection device and perform a
compound operation autonomously so that a predetermined point moves
along the target trajectory. The predetermined point in the
excavation attachment AT may be, for example, a predetermined point
on the back surface of the bucket 6.
[0188] The controller 30 is configured to perform the compound
operation repeatedly and may be configured to change the target
trajectory each time the compound operation is performed. Namely,
the target trajectory for the repeated compound operation such as a
boom up pivot operation may be updated for each execution of the
compound operation. For example, the controller 30 may change the
end position of the target trajectory (for example, the start
position of the earth removal) for each execution of the
autonomously controlled boom up pivot operation as stated with
reference to FIGS. 10A to 10C. Also, the controller 30 may change
the start position (for example, the excavation completion
position) of the target trajectory for each execution of the
autonomously controlled boom up pivot operation. Namely, at least
one of the start position and the end position of the target
trajectory may be updated for each execution of the boom up pivot
operation.
[0189] The shovel 100 may have the recording switch NS1 as a second
switch provided in the cabin 10. Then, the controller 30 may be
configured to acquire the information regarding the posture of the
excavation attachment AT when the recording switch NS1 is
operated.
[0190] The controller 30 may be configured to perform the compound
operation autonomously during operation of the automatic switch NS2
as the first switch or during execution of the pivot operation in
the state where the automatic switch NS2 is being operated. Then,
even if the automatic switch NS2 is not provided, the controller 30
may be configured to autonomously perform the compound operation
including the pivot operation on condition that the pivot operation
has been performed after recording the information regarding the
posture of the shovel 100.
[0191] The preferred embodiments of the present invention have been
described in detail above. However, the present invention is not
limited to the embodiments described above. Various modifications,
substitutions and the like may be applied to the embodiments
described above without departing from the scope of the present
invention. Also, the features described separately may be combined
unless there is a technical inconsistency.
[0192] For example, the shovel 100 may perform the autonomous
control function as described below to perform the compound
operation autonomously. FIG. 12 is a block diagram for illustrating
another exemplary arrangement of the autonomous control function.
In the example of FIG. 12, controller 30 includes functional
elements Fa to Fc and F1 to F6 related to execution of the
autonomous control. The functional elements may be composed of
software, hardware, or a combination of software and hardware.
[0193] The functional element Fa is configured to calculate the
earth removal start position. In this embodiment, before the earth
removal operation is actually started, the functional element Fa
calculates the position of the bucket 6 at starting the earth
removal operation as the earth removal start position based on
object data fed from the object detection device 70. Specifically,
the functional element Fa detects the state of earth and sand
already loaded on the platform of the dump truck DT based on the
object data fed from the object detection device 70. The state of
the earth and sand may be related to where the earth and sand is
loaded onto the platform of the dump truck DT, for example. Then,
the functional element Fa calculates the earth removal start
position based on the detected state of the earth and sand.
However, the functional element Fa may calculate the earth removal
start position based on the output of the capturing device 80.
Alternatively, the functional element Fa may calculate the earth
removal start position based on the posture of the shovel 100
recorded by the posture recording unit 30A in the previous earth
removal operation. Alternatively, the functional element Fa may
calculate the earth removal start position based on the output of
the posture detection device. In this case, for example, before the
earth removal operation is actually started, the functional element
Fa may calculate the position of the bucket 6 at the start time of
the earth removal operation as the earth removal start position
based on the current posture of the excavation attachment.
[0194] The functional element Fb is configured to calculate a dump
truck position. In this embodiment, the functional element Fb
calculates the respective positions of portions constituting the
loading platform of the dump truck DT as the dump truck positions
based on object data fed from the object detection device 70.
[0195] The functional element Fc is configured to calculate the
excavation completion position. In this embodiment, the functional
element Fc calculates the position of the bucket 6 at completion of
the excavation operation as the excavation completion position
based on the position of the claw edge of the bucket 6.
Specifically, the functional element Fc calculates the excavation
completion position based on the current position of the claw edge
of the bucket 6 that is calculated by the functional element F2 as
described below.
[0196] The functional element F1 is configured to generate a target
trajectory. In this embodiment, the functional element F1 generates
the target trajectory of the claw edge of the bucket 6 based on
object data fed from the object detection device 70 and the
excavation completion position calculated by the functional element
Fc. The object data may be information regarding an object existing
around the shovel 100 such as the position and shape of the dump
truck DT, for example. Specifically, the functional element F1
calculates the target trajectory based on the earth removal start
position calculated by the functional element Fa, the dump truck
position calculated by the functional element Fb, and the
excavation completion position calculated by the functional element
Fc.
[0197] The functional element F2 is configured to calculate the
current position of the claw edge. In this embodiment, the
functional element F2 calculates the coordinate point of the claw
edge of the bucket 6 as the current claw edge position based on the
boom angle .beta..sub.1 detected by the boom angle sensor S1, the
arm angle .beta..sub.2 detected by the arm angle sensor S2, the
bucket angle .beta..sub.3 detected by the bucket angle sensor S3,
and the pivot angle .alpha..sub.1 detected by the pivot angular
velocity sensor S5. The functional element F2 may use an output of
the body tilt sensor S4 to calculate the current claw edge
position.
[0198] The functional element F3 is configured to calculate the
next claw edge position. In this embodiment, the functional element
F3 calculates the claw edge position after a predetermined time as
a target claw edge position based on operation data fed from the
operation pressure sensor 29, the target trajectory generated by
the functional element F1, and the current claw edge position
calculated by the functional element F2.
[0199] The functional element F3 may determine whether the
deviation between the current claw edge position and the target
trajectory is within an acceptable range. In this embodiment, the
functional element F3 determines whether the distance between the
current claw edge position and the target trajectory is less than
or equal to a predetermined value. If the distance is less than or
equal to the predetermined value, the functional element F3
determines that the deviation is within the acceptable range and
calculates the target claw edge position. On the other hand, if the
distance exceeds the predetermined value, the functional element F3
determines that the deviation is not within the acceptable range
and decelerates or stops the movement of an actuator regardless of
the lever operation amount. According to this arrangement, the
controller 30 can prevent the autonomous control from being
continuously performed in the state where the claw edge position
deviates from the target trajectory.
[0200] The functional element F4 is configured to generate a
command value for the velocity of the claw edge. In this
embodiment, the functional element F4 calculates the velocity of
the claw edge required to move the current claw edge position to
the next claw edge position within a predetermined time as a
command value for the claw edge velocity based on the current claw
edge position calculated by the functional element F2 and the next
claw edge position calculated by the functional element F3.
[0201] The functional element F5 is configured to limit the command
value for the claw edge velocity. In this embodiment, if it is
determined based on the current claw edge position calculated by
the functional element F2 and an output of the object detection
device 70 that the distance between the claw edge and the dump
truck DT is less than a predetermined value, the functional element
F5 limits the command value for the claw edge velocity to a
predetermined upper limit value. In this manner, when the claw edge
approaches the dump truck DT, the controller 30 slows down the claw
edge velocity.
[0202] The functional element F6 is configured to calculate a
command value for operating an actuator. In this embodiment, the
functional element F6 calculates a command value .beta..sub.1r for
the boom angle .beta..sub.1, a command value .beta..sub.2r for the
arm angle .beta..sub.2, a command value .beta..sub.3r for the
bucket angle .beta..sub.3, and a command value .alpha..sub.1r for
the pivot angle .alpha..sub.1 based on a target claw edge position
calculated by the functional element F3 in order to move the
current claw edge position to the target claw edge position. Even
when the boom 4 is not operated, the functional element F6
calculates the command value .beta..sub.1r as necessary. This is to
automatically operate the boom 4. The same applies to the arm 5,
the bucket 6 and the pivot mechanism 2.
[0203] Next, the functional element F6 is described in detail with
reference to FIG. 13. FIG. 13 is a block diagram for illustrating
an exemplary arrangement of the functional element F6 that
calculates various command values.
[0204] The controller 30 further includes functional elements F11
to F13, F21 to F23, and F31 to F33 related to generation of the
command values, as shown in FIG. 13. The functional elements may
consist of software, hardware, or a combination of software and
hardware.
[0205] The functional elements F11 to F13 are functional elements
for the command value .beta..sub.1r, the functional elements F21 to
F23 are functional elements for the command value .beta..sub.2r,
the functional elements F31 to F33 are functional elements for the
command value .beta..sub.3r, and the functional elements F41 to F43
are functional elements for the command value .alpha..sub.1r.
[0206] The functional elements F11, F21, F31, and F41 are
configured to generate a current command fed to the proportional
valve 31. In this embodiment, the functional element F11 outputs a
boom current command to the boom control mechanism 31C, the
functional element F21 outputs an arm current command to the arm
control mechanism 31A, the functional element F31 outputs a bucket
current command to the bucket control mechanism 31D, and the
functional element F41 outputs a pivot current command to the pivot
control mechanism 31B.
[0207] The bucket control mechanism 31D is configured to cause the
pilot pressure corresponding to the control current corresponding
to a bucket cylinder pilot pressure command to be applied to the
control valve 174 serving as a bucket control valve. The bucket
control mechanism 31D may be, for example, the proportional valve
31DL and the proportional valve 31DR in FIG. 3D.
[0208] The functional elements F12, F22, F32, and F42 are
configured to calculate the displacement amount of a spool
constituting a spool valve. In this embodiment, the functional
element F12 calculates the displacement amount of a boom spool
constituting the control valve 175 with respect to the boom
cylinder 7 based on an output of a boom spool displacement sensor
S7. The functional element F22 calculates the displacement amount
of an arm spool constituting the control valve 176 with respect to
an arm cylinder 8 based on an output of an arm spool displacement
sensor S8. The functional element F32 calculates the displacement
amount of a bucket spool constituting the control valve 174 with
respect to a bucket cylinder 9 based on an output of a bucket spool
displacement sensor S9. The functional element F42 calculates the
displacement amount of a swivel spool constituting the control
valve 173 with respect to a pivot hydraulic motor 2A based on an
output of a pivot spool displacement sensor S2A. Note that the
bucket spool displacement sensor S9 is a sensor for detecting the
displacement amount of the spool constituting the control valve
174.
[0209] The functional elements F13, F23, F33, and F43 are
configured to calculate the rotational angle of a workpiece. In
this embodiment, the functional element F13 calculates the boom
angle .beta..sub.1 based on an output of the boom angle sensor S1.
The functional element F23 calculates the arm angle .beta..sub.2
based on an output of the arm angle sensor S2. The functional
element F33 calculates the bucket angle .beta..sub.3 based on an
output of the bucket angle sensor S3. The functional element F43
calculates the pivot angle .alpha..sub.1 based on an output of the
pivot angular velocity sensor S5.
[0210] Specifically, the functional element F11 basically generates
a boom current command to the boom control mechanism 31C such that
the difference between the command value .beta..sub.1r generated by
the functional element F6 and the boom angle .beta..sub.1
calculated by the functional element F13 becomes zero. At that
time, the function element F11 adjusts the boom current command so
that the difference between the target boom spool displacement
amount derived from the boom current command and the boom spool
displacement amount calculated by the function element F12 becomes
zero. Then, the functional element F11 outputs the adjusted boom
current command to the boom control mechanism 31C.
[0211] The boom control mechanism 31C changes the opening area in
response to the boom current command to apply the pilot pressure
corresponding to the size of the opening area to a pilot port of
the control valve 175. The control valve 175 moves a boom spool
corresponding to the pilot pressure to cause the hydraulic oil to
flow into the boom cylinder 7. The boom spool displacement sensor
S7 detects the displacement of the boom spool and feeds back the
detection result to the functional element F12 of the controller
30. The boom cylinder 7 extends or contracts in response to the
inflow of the hydraulic oil to move the boom 4 up or down. The boom
angle sensor S1 detects the rotation angle of the vertically moving
boom 4 and feeds back the detection result to the functional
element F13 of the controller 30. The functional element F13 feeds
back the calculated boom angle .beta..sub.1 to the functional
element F4.
[0212] The functional element F21 basically generates an arm
current command for the arm control mechanism 31A such that the
difference between the command value .beta..sub.2r generated by the
functional element F6 and the arm angle .beta..sub.2 calculated by
the functional element F23 becomes zero. At that time, the
functional element F21 adjusts the arm current command so that the
difference between a target arm spool displacement amount derived
from the arm current command and the arm spool displacement amount
calculated by the functional element F22 becomes zero. Then, the
functional element F21 feeds the adjusted arm current command to
the arm control mechanism 31A.
[0213] The arm control mechanism 31A changes the opening area in
response to an arm current command to apply the pilot pressure
corresponding to the size of the opening area to a pilot port of
the control valve 176. The control valve 176 moves the arm spool in
response to the pilot pressure to cause the hydraulic oil to flow
into the arm cylinder 8. The arm spool displacement sensor S8
detects the displacement of the arm spool and feeds back the
detection result to the functional element F22 of the controller
30. The arm cylinder 8 expands and contracts in response to the
inflow of the hydraulic oil to open and close the arm 5. The arm
angle sensor S2 detects the rotation angle of the opening and
closing arm 5 and feeds back the detection result to the functional
element F23 of the controller 30. The functional element F23 feeds
back the calculated arm angle .beta..sub.2 to the functional
element F4.
[0214] The functional element F31 basically generates a bucket
current command to the bucket control mechanism 31D such that the
difference between the command value .beta..sub.3r generated by
functional element F6 and the bucket angle .beta..sub.3 calculated
by functional element F33 becomes zero. At that time, the
functional element F31 adjusts the bucket current command so that
the difference between a target bucket spool displacement amount
derived from the bucket current command and the bucket spool
displacement amount calculated by the functional element F32
becomes zero. Then, the functional element F31 feeds the adjusted
bucket current command to the bucket control mechanism 31D.
[0215] The bucket control mechanism 31D changes the opening area in
response to a bucket current command to apply the pilot pressure
corresponding to the size of the opening area to a pilot port of
the control valve 174. The control valve 174 moves a bucket spool
in response to the pilot pressure to cause the hydraulic oil to
flow into the bucket cylinder 9. The bucket spool displacement
sensor S9 detects the displacement of the bucket spool and feeds
back the detection result to the functional element F32 of the
controller 30. The bucket cylinder 9 extends and contracts in
response to the inflow of the hydraulic oil to open and close the
bucket 6. The bucket angle sensor S3 detects the rotation angle of
the opening and closing bucket 6 and feeds back the detection
result to the functional element F33 of the controller 30. The
functional element F33 feeds back the calculated bucket angle
.beta..sub.3 to the functional element F4.
[0216] The functional element F41 basically generates a pivot
current command for the pivot control mechanism 31B such that the
difference between the command value .alpha..sub.1r generated by
the functional element F6 and the pivot angle .alpha..sub.1
calculated by the functional element F43 becomes zero. At this
time, the function element F41 adjusts the pivot current command so
that the difference between a target pivot spool displacement
amount derived from the pivot current command and the pivot spool
displacement amount calculated by the function element F42 becomes
zero. Then, the functional element F41 feeds the adjusted pivot
current command to the pivot control mechanism 31B.
[0217] The pivot control mechanism 31B changes the opening area in
response to the pivot current command to apply the pilot pressure
corresponding to the size of the opening area to a pilot port of
the control valve 173. The control valve 173 moves the pivot spool
in response to the pilot pressure to cause the hydraulic oil to
flow into the pivot hydraulic motor 2A. The pivot spool
displacement sensor S2A detects the displacement of the pivot spool
and feeds back the detection result to the functional element F42
of the controller 30. The pivot hydraulic motor 2A rotates
corresponding to the inflow of the hydraulic oil to pivot the upper
pivot body 3. The pivot angular velocity sensor S5 detects the
pivot angle of the upper pivot body 3 and feeds back the detection
result to the functional element F43 of the controller 30. The
function element F43 feeds back the calculated pivot angle
.alpha..sub.1 to the function element F4.
[0218] As stated above, the controller 30 forms a three-stage
feedback loop for each workpiece. Namely, the controller 30
constitutes a feedback loop for the spool displacement amount, a
feedback loop for the pivot angle of the workpiece, and a feedback
loop for the claw edge position. Therefore, the controller 30 can
precisely control the movement of the claw edge of the bucket 6 in
the autonomous control.
[0219] Also, in the embodiments stated above, a hydraulic control
lever including a hydraulic pilot circuit is disclosed.
Specifically, in the hydraulic pilot circuit for the left control
lever 26L functioning as an arm control lever, the hydraulic oil
supplied from the pilot pump 15 to a remote control valve of the
left control lever 26L is transmitted to a pilot port of the
control valve 176 serving as an arm control valve at a flow rate
corresponding to the opening of the remote control valve that is
opened and closed by tilting of the left control lever 26L.
[0220] Instead of the hydraulic operation lever including such a
hydraulic pilot circuit, however, an electric operation lever
including an electric pilot circuit may be employed. In this case,
the lever operation amount of the electric operation lever is fed
to the controller 30 as an electric signal. Also, a solenoid valve
is also disposed between the pilot pump 15 and a pilot port of each
control valve. The solenoid valve is configured to operate in
response to an electrical signal from the controller 30. According
to this arrangement, if a manual operation is performed by means of
the electric operation lever, the controller 30 can control the
solenoid valves by means of the electric signal corresponding to
the lever operation amount to increase or decrease the pilot
pressure and move the respective control valve within the control
valve 17. Note that each control valve may be composed of a
solenoid spool valve. In this case, the solenoid spool valve
operates in response to an electric signal from the controller 30
corresponding to the lever operation amount of the electric control
lever.
[0221] If an electric operation system with an electric control
lever is employed, the controller 30 can perform an autonomous
control function more easily than a hydraulic operation system with
a hydraulic operation lever. FIG. 14 shows an exemplary arrangement
of an electric operation system. Specifically, the electric
operation system of FIG. 14 is one example of a boom operation
system, which is mainly composed of a pilot pressure operation type
of control valve 17, a boom operation lever 26A as an electric
operation lever, a controller 30, a solenoid valve 60 for the boom
up operation, and a solenoid valve 62 for the boom down operation.
The electric operation system of FIG. 14 may also be analogously
applied to an arm operation system, a bucket operation system, and
the like.
[0222] A pilot pressure actuation type of control valve 17 includes
a control valve 175 (see FIG. 2) for the boom cylinder 7, a control
valve 176 (see FIG. 2) for the arm cylinder 8, and a control valve
174 (see FIG. 2) for the bucket cylinder 9. The solenoid valve 60
is configured to adjust the flow path area of a conduit that
couples the pilot pump 15 to the upside pilot port of the control
valve 175. The solenoid valve 62 is configured to adjust the flow
path area of a conduit that couples the pilot pump 15 to the
downside pilot port of the control valve 175.
[0223] If a manual operation is performed, the controller 30
generates a boom up operation signal (electric signal) or a boom
down operation signal (electric signal) in response to an operation
signal (electric signal) fed from an operation signal generation
unit of the boom operation lever 26A. The operation signal fed from
the operation signal generation unit of the boom operation lever
26A is an electric signal that varies depending on the operation
amount and the operation direction of the boom operation lever
26A.
[0224] Specifically, if the boom operation lever 26A is operated in
the boom up direction, the controller 30 outputs a boom up
operation signal (electric signal) corresponding to the lever
operation amount to the solenoid valve 60. The solenoid valve 60
adjusts the flow path area in response to the boom up operation
signal (electric signal) and controls the pilot pressure serving as
a boom up operation signal (pressure signal) applied to the upside
pilot port of the control valve 175. Similarly, if the boom
operation lever 26A is operated in the boom down direction, the
controller 30 outputs a boom down operation signal (electric
signal) corresponding to the lever operation amount to the solenoid
valve 62. The solenoid valve 62 adjusts the flow path area in
response to the boom down operation signal (electric signal) and
controls the pilot pressure serving as a boom down operation signal
(pressure signal) applied to the downside pilot port of the control
valve 175.
[0225] If the autonomous control is performed, the controller 30
generates a boom up operation signal (electric signal) or a boom
down operation signal (electric signal) in accordance with a
correction operation signal (electric signal) instead of an
operation signal (electric signal) fed from the operation signal
generation unit of the boom operation lever 26A. The correction
operation signal may be an electric signal generated by the
controller 30 or an electric signal generated by an external
controller other than the controller 30.
[0226] The information obtained by the shovel 100 may be shared
with an administrator and other operators of the shovel through a
shovel management system SYS as shown in FIG. 15. FIG. 15 is a
schematic diagram for illustrating an exemplary arrangement of the
shovel management system SYS. The management system SYS is a system
that manages one or more shovels 100. In this embodiment, the
management system SYS is mainly composed of the shovel 100, an
assistance device 200, and a management device 300. Each of the
shovel 100, the assistance device 200, and the management device
300 in the management system SYS may be a single unit or multiple
units. In the example of FIG. 15, the management system SYS
includes one shovel 100, one assistance device 200, and one
management device 300.
[0227] The assistance device 200 is typically a portable terminal
device, such as a notebook PC, a tablet PC or a smartphone carried
by a worker or the like at a construction site. The assistance
device 200 may be a computer carried by an operator of shovel 100.
The assistance device 200 may be a fixed terminal device.
[0228] The management device 300 is typically a fixed terminal
device, such as a server computer installed in a management center
or the like outside a construction site. The management device 300
may be a portable computer (for example, a portable terminal device
such as a notebook PC, a tablet PC or a smartphone).
[0229] At least one of the assistance device 200 and the management
device 300 may have a monitor and a remote operation device. In
this case, the operator may operate the shovel 100 using the remote
operation device. The remote operation device may be connected to
the controller 30 through a communication network such as a
wireless communication network. Hereinafter, exchanges of
information between the shovel 100 and the management apparatus 300
are described, but the following description applies similarly to
exchanges of information between the shovel 100 and the assistance
apparatus 200.
[0230] In the above-stated management system SYS of the shovel 100,
the controller 30 of the shovel 100 may transmit information to the
management apparatus 300 regarding at least one of the time and
location where the autonomous control is started or stopped, the
target trajectory used in the autonomous control, and the
trajectory actually traced by a predetermined portion during the
autonomous control. At this time, the controller 30 may transmit at
least one of an output of the object detection device 70 and an
image or the like captured by the capturing device 80 to the
management device 300. The image may be a plurality of images
captured during a predetermined period including the period during
which the autonomous control has been performed. Additionally, the
controller 30 may transmit information regarding at least one of
the following to the management device 300: data about work
contents of the shovel 100 during a predetermined period of time
including the period during which the autonomous control has been
performed, data about the posture of the shovel 100, and data about
the posture of an excavation attachment. This is to make the
information regarding the worksite available to the administrator
using the management device 300. The data regarding work contents
of the shovel 100 is at least one of the number of loading times
that is the number of times the earth removal has been performed,
information regarding a to-be-loaded object such as earth and sand
loaded on the platform of the dump truck DT, the type of the dump
truck DT for the loading operation, information regarding the
position of the shovel 100 in the loading operation, information
regarding the working environment, and information regarding the
operation of the shovel 100 in the loading operation. The
information regarding the to-be-loaded object is at least one of
the weight and type of the loaded object in each earth removal
operation, the weight and type of the loaded object in each dump
truck DT, and the weight and type of the loaded object in each day
loading operation. The information regarding the working
environment may be, for example, information regarding the slope of
the ground around the shovel 100 or information regarding the
weather around the work site. The information regarding the
operation of the shovel 100 is at least one of a pilot pressure and
a hydraulic oil pressure in a hydraulic actuator, for example.
[0231] In this manner, the management system SYS of the shovel 100
according to embodiments of the present invention allows the
information regarding the shovel 100 acquired during a
predetermined period, including the period during which the
autonomous control by the shovel 100 is performed, to be shared
with the administrator and other operators of the shovel.
* * * * *